Wireless communication methods and apparatus supporting different types of wireless communciation approaches

ABSTRACT

A wireless terminal supports both peer to peer communications and access node based communications. The wireless terminal considers and evaluates communications link alternatives and selects between (i) communication using a peer to peer link and (ii) communications using a link, with a base station serving as an access node, Received signals corresponding to each of the link alternatives are used in performing link quality determinations. In one example, a received user beacon signal from a peer wireless terminal is the received signal used for the peer to peer link evaluation and a: base station beacon signal is the received signal used for the access node link evaluation. A link is selected as a function of quality determination, predicted data throughput, link maintenance energy requirements, and/or least cost routing determination information.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/621,988 filed Jan. 10, 2007, entitled “WIRELESSCOMMUNICATION METHODS AND APPARATUS SUPPORTING DIFFERENT TYPES OFWIRELESS COMMUNICATION APPROACHES” that claims the benefit of U.S.Provisional Patent Application Ser. No. 60/758,011 filed on Jan. 11,2006, entitled “METHODS AND APPARATUS FOR USING BEACON SIGNALS FORIDENTIFICATION, SYNCHRONIZATION OR ACQUISITION IN AN AD HOC WIRELESSNETWORK”, and U.S. Provisional Patent Application Ser. No. 60/758,010filed on Jan. 11, 2006, entitled “METHODS AND APPARATUS FOR FACILITATINGIDENTIFICATION, SYNCHRONIZATION OR ACQUISITION USING BEACON SIGNALS”,and U.S. Provisional Patent Application Ser. No. 60/758,012 filed onJan. 11, 2006, entitled “METHODS AND APPARATUS FOR USING BEACON SIGNALSIN A COGNITIVE RADIO NETWORK”, and U.S. Provisional Patent ApplicationSer. No. 60/863,304 filed on Oct. 27, 2006, and U.S. Provisional PatentApplication Ser. No. 60/845,052 filed on Sep. 15, 2006, and U.S.Provisional Patent Application Ser. No. 60/845,051 filed on Sep. 15,2006, each of which is hereby incorporated by reference and all of whichare assigned to the assignee hereof.

FIELD

The present invention is directed to methods and apparatus for signalingin wireless communication and, more particularly, to methods andapparatus for using signals for identification, synchronization and/oracquisition.

BACKGROUND

In a wireless network, e.g., an ad hoc network, in which a networkinfrastructure does not exist, a terminal has to combat certainchallenges in order to set up a communication link with another peerterminal. One challenge is to make the terminals in the vicinity to besynchronized to a common timing and/or frequency reference. A commontiming and/or frequency reference is crucial for the terminals toestablish communication links. For example, in an ad hoc network, when aterminal just powers up or moves into a new area, the terminal may haveto first find out whether another terminal is present in the vicinitybefore any communication between the two terminals can start. Thegeneral solution is to let the terminal transmit and/or receive signalsaccording to certain protocol. However, if the terminals do not havecommon timing notation, it is possible that when a first terminal istransmitting a signal and a second terminal is not in the receivingmode, the transmitted signal does not help the second terminal to detectthe presence of the first terminal.

In view of the above discussion, it should be appreciated that there isa need for new and improved ways for identification, acquisition, and/orsynchronization, especially in a wireless system i which the networkinfrastructure may not be available.

SUMMARY

Various embodiments are directed to methods and apparatus involving theconsideration and selection between alternative communications links;one alternative link uses a base station as an access point while theother alternative link is a peer to peer link. Some embodiments aredirected to a wireless terminal, e.g., mobile node, which supports bothpeer to peer communications and communication with a base station, thewireless terminal selecting between a first link with a base stationserving as an access node and a second link with a peer node as part ofpeer to peer communications. An exemplary method of operating a wirelessterminal which supports both peer to peer communication andcommunication via a base station, comprises: receiving a first signalfrom a first communications band, the first signal being from a basestation; determining from said first signal link quality of a first linkbetween said base station and said wireless terminal; receiving a secondsignal from a second communications band which is different from saidfirst communications band, said second signal being from a peer wirelessterminal; determining from said second signal link quality of a secondlink between said wireless terminal and said peer wireless terminal; andselecting between said first and second links for a communicationssession based on the determined quality of said first and second links.An exemplary wireless terminal which supports both peer to peercommunication and communication via a base station, includes: a receivermodule for receiving a first signal from a first communications band,the first signal being from a base station and for receiving a secondsignal from a second communications band which is different from saidfirst communications band, said second signal being from a peer wirelessterminal; a base station link quality determination module fordetermining from said first signal link quality of a first link betweensaid base station and said wireless terminal; a peer to peer linkquality determination module for determining from said second signallink quality of a second link between said wireless terminal and saidpeer wireless terminal; and a link selection module for selectingbetween said first and second links for a communications session basedon the determined quality of said first and second links.

While various embodiments have been discussed in the summary above, itshould be appreciated that not necessarily all embodiments include thesame features and some of the features described above are not necessarybut can be desirable in some embodiments. Numerous additional features,embodiments and benefits are discussed in the detailed description whichfollows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary communications system supporting bothaccess node base communications and peer to peer communicationsimplemented in accordance with various embodiments.

FIG. 2 illustrates two exemplary spectrum bands available to be used ina geographic area.

FIG. 3 illustrates a ladder diagram of an exemplary method of obtainingand utilizing spectrum information implemented in accordance withvarious embodiments.

FIG. 4 illustrates an example of utilizing timing synchronizationinformation implemented in accordance with various embodiments.

FIG. 5 illustrates an exemplary diagram of receiving paging and being ina peer-to-peer or TDD session implemented in accordance with variousembodiments.

FIG. 6 illustrates a flowchart of an exemplary method of operating awireless terminal to determine data rates corresponding to potentiallinks with alternative nodes, e.g., a base station and a peer wirelessterminal, and selecting a node to communicate with in accordance withvarious embodiments.

FIG. 7 illustrates a ladder diagram of an exemplary method of usingbeacon and/or broadcast channels to temporarily convert infrastructurespectrum band for non-infrastructure based service implemented inaccordance with various embodiments.

FIG. 8 illustrates two exemplary ad hoc networks in two geographicareas, implemented in accordance with various embodiments.

FIG. 9 illustrates exemplary spectrum bands available to be used in twodifferent geographic areas.

FIG. 10 illustrates exemplary system beacon signals transmitted in thead hoc networks in two different geographic areas.

FIG. 11 illustrates an exemplary wireless terminal implemented inaccordance with various embodiments.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is a drawingof a flowchart of an exemplary method of operating a wireless terminalto communicate with another communications device in accordance withvarious embodiments.

FIG. 13 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 14 is a drawing of a flowchart of an exemplary method of operatinga wireless terminal which supports both peer to peer communications andcommunications with a base station in accordance with variousembodiments.

FIG. 15 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 16 is a drawing of a flowchart of an exemplary method of operatinga base station in accordance with various embodiments.

FIG. 17 is a drawing of an exemplary base station in accordance withvarious embodiments.

FIG. 18 is a drawing of an exemplary beacon signal transmissionapparatus in accordance with various embodiments.

FIG. 19 is a drawing of a flowchart of an exemplary method of operatinga beacon signal transmitter device in accordance with variousembodiments.

FIG. 20 comprising the combination of FIG. 20A and FIG. 20B is a drawingof a flowchart of an exemplary method of operating a base station inaccordance with various embodiments.

FIG. 21 is a drawing of an exemplary base station in accordance withvarious embodiments.

FIG. 22 is a drawing of a flowchart of an exemplary method of operatinga wireless device, e.g., a mobile node, in accordance with variousembodiments.

FIG. 23 is a drawing of an exemplary wireless terminal, e.g., mobilenode in accordance with various embodiments.

FIG. 24 is a drawing of a flowchart of an exemplary method of operatinga mobile communications device in a system including a base station inaccordance with various embodiments.

FIG. 25 is a drawing of an exemplary wireless terminal, e.g., mobilenode, in accordance with various embodiments.

FIG. 26 is a drawing of a flowchart of an exemplary method of operatinga wireless device, e.g., a mobile node, in accordance with variousembodiments.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawingof a flowchart of an exemplary communications method in accordance withvarious embodiments.

FIG. 29 is a drawing of an exemplary wireless terminal, e.g., mobilenode, in accordance with various embodiments.

FIG. 30 is a drawing of an exemplary communications system in accordancewith various embodiments.

FIG. 31 is a drawing of an exemplary wireless communications systemwhich supports both peer to peer communications and cellularcommunications in accordance with various embodiments.

FIG. 32 is a drawing illustrating exemplary beacon burst time positionhopping in accordance with various embodiments.

FIG. 33 is a drawing illustrating exemplary beacon burst time positionhopping and beacon symbol tone hopping in accordance with variousembodiments.

FIG. 34 is a drawing illustrating exemplary coordinated timing in a peerto peer communications band in accordance with various embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary communications system 100 supportingboth access node based communications and peer to peer communicationsimplemented in accordance with various embodiments. An infrastructurebase station 108 is coupled with a big network, e.g., the Internet,through a network node 110 via a wired link 111. The base station 108provides services to the wireless terminals, such as a first wirelessterminal 102 and a second wireless terminal 104, in the geographic area106 via a wireless spectrum band. The wireless spectrum band is calledthe infrastructure band.

In addition to the infrastructure band, a different spectrum band,referred to as non-infrastructure band may also be, and sometimes is,available to be used by the wireless terminals in the same geographicarea. Thus wireless terminals (102, 104) can participate in an ad hocpeer to peer communication session using non-infrastructure band. FIG. 2includes drawing 200 which illustrates the notion of the infrastructureband 202 and the non-infrastructure band 204. The two bands are in someembodiments non-overlapping. In a typical embodiment, the infrastructureband includes a pair of FDD (frequency division duplex) spectrum bandsor an unpaired TDD (time division duplex) spectrum band. Thenon-infrastructure band includes an unpaired spectrum and can be usedfor ad hoc peer-to-peer communication. In some embodiments, thenon-infrastructure band is also used for TDD. In some embodiments, thesame infrastructure base station, which provides the service in theinfrastructure band, may also provide service in the non-infrastructureband.

In an exemplary embodiment, the infrastructure base station transmits abeacon signal in the infrastructure band. The beacon signal is a specialsignal that occupies a small fraction of the total minimum transmissionunits in the available spectrum. In some embodiments, a beacon signalburst including at least one beacon symbol. In some embodiments, thebeacon symbols corresponding to a beacon signal occupy a small fraction,e.g., in some embodiments no more than 0.1%, of the total minimumtransmission units in the available spectrum air link resource. Aminimum transmission unit is the minimum unit of air link resource touse for communication. In some exemplary frequency division multiplexingsystems, e.g., some OFDM systems, a minimum transmission unit is asingle tone over a symbol transmission period, sometimes referred to asa tone-symbol. In addition, the average transmission power of the beaconsymbols of the beacon signal is much higher, e.g., at lest 10 dBs or atleast 16 dB higher, than the average transmission power of data andcontrol signals per minimum transmission unit when the terminaltransmitter is in an ordinary data session.

In addition, the infrastructure base station, in some embodiments, usesa broadcast channel, including the beacon signal, to send the systeminformation including the frequency (e.g., carrier) location of thenon-infrastructure spectrum band and/or the type of service provided inthe band, e.g., TDD (time division duplex) or ad hoc networking.

FIG. 3 illustrates an exemplary ladder diagram 300 of an exemplarymethod of obtaining and utilizing spectrum information implemented by awireless terminal in accordance with various embodiments. Drawing 300includes time axis 301, infrastructure base station 302 and wirelessterminal 304.

The wireless terminal 304 knows the frequency location of theinfrastructure spectrum band. The wireless terminal 304 first tunes tothe infrastructure spectrum band (306) and searches for the beaconsignal (308) to find the availability of the infrastructure basestation. The infrastructure base station 302 transmits beacon signal 310which is received and detected (312) by wireless terminal 304. Once thewireless terminal 304 detects the beacon signal (310), the wirelessterminal 304 synchronizes (314) itself with the infrastructure basestation 302. The infrastructure base station 302 transmits broadcastsignals 316, in addition to beacon signals 310. In some embodiments,wireless terminal 304 further receives the broadcast signals 316 andrecovers system information from a broadcast channel to obtain thefrequency location information of the non-infrastructure spectrum band(318). The wireless terminal 304, in various embodiments, derives timingand/or frequency information from at least one of the broadcast channelsand/or the beacon signal (320). The wireless terminal then tunes to thefrequency location of the non-infrastructure band to obtain the TDDand/or ad hoc service (322). The wireless terminal 304 uses the timingand/or frequency information derived in step 320 when the terminal 304obtains the service in the non-infrastructure band (324).

Unlike the infrastructure band, the non-infrastructure band may not, andsometimes does not, have a natural source from which each of thewireless terminals can derive synchronization information. When each ofthe wireless terminals use the timing and/or frequency informationderived from a common source, i.e., the infrastructure base station inthe infrastructure spectrum band, the wireless terminals now have acommon timing and/or frequency reference. Advantageously this enablessynchronization of the terminals in the non-infrastructure band. Toelaborate, drawing 400 of FIG. 4 illustrates an example of utilizingtiming synchronization information obtained from infrastructuresignaling in an associated non-infrastructure band.

The horizontal axis 401 represents time. The infrastructure base stationtransmits the beacon signal 402 in the infrastructure band. The beaconsignal 402 includes a sequence of beacon signal bursts, 404, 406, 408,and so on. Suppose that two wireless terminals derive the timinginformation from the beacon signal 402, and then tune to thenon-infrastructure band, which is used for peer-to-peer ad hoc network.

Either of the two wireless terminals has to be aware of the presence ofthe other before they can set up a peer to peer communication session.In one embodiment, either wireless terminal transmits or receives a userbeacon signal burst in the non-infrastructure band in a time interval,which is a function of the timing of the beacon signal burst sent by theinfrastructure base station.

For example, in FIG. 4, the time interval starts from a time instancethat has known time offset 410 from the beginning 412 of a beacon signalburst sent by the infrastructure base station. Either wireless terminalin some embodiments randomly chooses whether to transmit or receive. Inthe exemplary scenario shown in FIG. 4, the first wireless terminalchooses to transmit, as indicated by exemplary user beacon signal burst414 transmitted into the non-infrastructure spectrum band, while thesecond wireless terminal chooses to receive. The second wirelessterminal controls its receiver on time interval for beacon monitoring inthe non-infrastructure spectrum band such as to include interval 416corresponding to the first wireless terminal's beacon transmission, andthe second wireless terminal detects the user beacon signal sent by thefirst wireless terminal. The second wireless terminal may, and sometimesdoes, then start to establish a communication link with the firstwireless terminal. However, if both wireless terminals choose totransmit or to receive, then they may not find each other in this timeinterval. The wireless terminals can probabilistically find each otherin subsequent time intervals.

Note that in the absence of the common timing reference, the wirelessterminals may have to be in the listening mode in a much longer timeinterval in order to detect a user beacon signal burst. The commontiming reference thus helps the wireless terminals to find each othermuch more rapidly and in a more power efficient manner.

In another embodiment, the base station additionally transmits thebeacon signal in the second spectrum band, so that if the wirelessterminal directly tunes to the second spectrum band, the wirelessterminal can derive the desired common timing and/or frequency referencefrom the beacon signal.

FIG. 5 illustrates an exemplary state diagram 500 of receiving pagingand being in a peer-to-peer or TDD session implemented in accordancewith various embodiments. Operation starts in step 501, where thewireless terminal is powered on and initialized and then proceeds tostep 502.

A wireless terminal and the networking paging agent, e.g., a server onthe network side, have an agreement on when a page for the wirelessterminal, if any, will be sent to the wireless terminal via theinfrastructure base station. The wireless terminal sets a timer tomonitor potential incoming pages (502). In a typical paging system, thewireless terminal may go to a power saving mode until the timer expires.In accordance with a novel feature of various exemplary embodiments, thewireless terminal tunes to the non-infrastructure spectrum band andobtains service (504), e.g., TDD or peer-to-peer communication service.When the timer expires, the wireless terminal tunes to theinfrastructure spectrum band and monitors a paging channel (506). If theterminal is not paged, the wireless terminal may set the timer again forthe next page monitoring time (502). Otherwise, the wireless terminal isbeing paged, needs to process the received page, and processes thereceived page (508).

In some embodiments, there is a common time interval during which eachof the wireless terminals or a large subset of the wireless terminalsusing the non-infrastructure spectrum band suspend the sessions in thenon-infrastructure spectrum band and check pages in the infrastructurespectrum band. Advantageously, this synchronized suspension ofnon-infrastructure sessions helps reduce the wastage of resource in thenon-infrastructure band.

FIG. 6 illustrates a flowchart 600 of an exemplary method of operating awireless terminal to determine data rates corresponding to potentiallinks with alternative nodes, e.g., a base station and a peer wirelessterminal, and selecting a node to communicate with in accordance withvarious embodiments.

A base station transmits a beacon signal. In some embodiments, in thenon-infrastructure band, the infrastructure base station transmits abeacon signal, and a wireless terminal also transmits a user beaconsignal. Thus, in such an embodiment, a wireless terminal can have itsreceiver tuned to the non-infrastructure band and receive base stationbeacon signals and wireless terminal user beacon signals. Differentbeacon signals, in some embodiments, differentiate from each other byusing different beacon tone hopping sequences and/or different timing ofbeacon bursts. A transmitter, e.g., the base station or the wirelessterminal, in some embodiments is also used to transmit data/controlchannels. In accordance with various embodiments, the transmission powerof the beacon signal and/or that of the data/control channels are suchthat from the received beacon signal or signals, a receiver can predictthe signal quality of the data/control channels, and/or compare thesignal quality from multiple transmitters.

In some embodiments, the transmission power of the base station beaconsignal is the same for each base station. In some embodiments, thetransmission power of the user beacon signal is the same for each of thewireless terminals transmitting user beacon signals. In someembodiments, the transmission power of base station and user beacons arethe same. In some embodiments, the data/control channels are sent at atransmission power, which is a function of the transmission power of thebeacon signal. For example, the per minimum transmission unittransmission power of the data channel, at a given coding and modulationrate, is a fixed dB amount, e.g., 10 dBs or 16 dBs, below thetransmission power of the beacon signal.

With regard to FIG. 6, operation of the exemplary method starts in step601, where the wireless terminal is powered on and initialized andproceeds to step 602 for each link being considered. In step 602 thewireless terminal receives a beacon signal from a transmitter, e.g., aninfrastructure base station transmitter or a wireless terminaltransmitter, and then, in step 604 the wireless terminal measures thereceived power. Operation proceeds from step 604 to step 606. In step606, the wireless terminal then predicts the received power of user datasignals, e.g., a data/control traffic channel, assuming that thewireless terminal is receiving the channel from the transmitter, usingthe known power relationship between the traffic channel and the beaconsignal. In step 608, the wireless terminal further measures thebackground noise and interference. Then, in step 610, the wirelessterminal predicts the signal quality, e.g., signal-to-noise ratio (SNR)of a data session if the wireless terminal is to set up a session withthe device, e.g., base station or wireless terminal, corresponding tothe transmitter, and sees whether the signal quality and thus the datarate of the data session are sufficient. In some cases, the wirelessterminal may, and sometimes does, receive beacon signals from multipletransmitters. In step 611, the wireless terminal compares the signalquality from those transmitters considered and selects a proper one withwhich to communicate, thus selecting the base station or wirelessterminal corresponding to the selected transmitter.

FIG. 7 illustrates a ladder diagram 700 of an exemplary method of usingbeacon and/or broadcast channels to temporarily convert infrastructurespectrum band for non-infrastructure based service implemented inaccordance with various embodiments. Unlike some of the otherembodiments presented, this exemplary embodiment has an infrastructureband but does not need a fixed non-infrastructure band.

the vertical axis 702 represents time. The infrastructure base station704 checks (708) whether there is any wireless terminal using the normalservice provided by the infrastructure base station, such as normal FDDor TDD service. The normal service is referred to as infrastructurebased service. If the answer is no, then the infrastructure base stationcan convert (710) the infrastructure spectrum band to become anon-infrastructure band, which can be used by non-infrastructure basedservice, such as peer-to-peer communication service. To do so, the basestation sends at least one of a beacon signal (712) and a non-beaconbroadcast signal (714) to indicate that the infrastructure band has beenconverted to non-infrastructure band. Upon the reception of that signal,the wireless terminals, e.g., wireless terminal 706, in the area canstart to use non-infrastructure service in the band (716).

At a later time, the infrastructure base station 704 may decide (718) toreturn the spectrum band to the infrastructure based service. Theinfrastructure base station in some embodiments does so because of atleast one of the following reasons:

-   1) the infrastructure base station senses that some wireless    terminals may need the infrastructure base station senses that some    wireless terminals may need the infrastructure based service; 2)    some timer has expired, in which case the timer is used to control    the time duration of the infrastructure spectrum band being used as    a non-infrastructure band. To do so, the base station 704 sends at    least one of a beacon signal (720) and a non-beacon broadcast signal    (722) to indicate that the infrastructure band has returned to the    infrastructure based service. Upon the reception of that signal, the    wireless terminals in the area, e.g., wireless terminal 706, can    cease to use non-infrastructure service in the band (724). For    example, if a wireless terminal has an on-going peer-to-peer    communication session, the wireless terminal shall stop or suspend    the session.

FIG. 8 illustrates in drawing 800 two exemplary ad hoc networks (801,851) in two geographic areas (806, 856), respectively, implemented inaccordance with various embodiments.

The ad hoc network 801 in geographic area A 806 includes a number ofterminals, such as a first wireless terminal 802 and a second wirelessterminal 804, and a special transmitter 808, which transmits a systembeacon signal in accordance with the exemplary embodiment. The wirelessterminals, in some embodiments, use the system beacon signal as a systemreference signal. The special transmitter in some embodiments is coupledto a big network, e.g., the Internet, through a network node 810, e.g.,via a wired link. The special transmitter 808, in some embodiments, isalso used to have peer-to-peer sessions with a wireless terminal.Alternatively, in some embodiments the transmitter may be, and sometimesis a standalone unit.

The ad hoc network 851 in geographic area B 856 includes a number ofterminals, such as a third wireless terminal 852 and a fourth wirelessterminal 854, and a special transmitter 858, which transmits a systembeacon signal in accordance with the exemplary embodiment. The specialtransmitter in some embodiments is coupled to a big network, e.g., theInternet, through a network node 860, e.g., via a wired link.

In this exemplary embodiment, the spectrum availability is a function ofthe environment. Here, infrastructure spectrum bands may not exist. Forexample, drawing 900 of FIG. 9 shows exemplary spectrum bands availablein geographic area A 806 and in geographic area B 856. Those spectrumbands are non-infrastructure.

The horizontal axis 905 represents frequency. The upper portion 901 ofthe FIG. 9 shows that there are two spectrum bands, 902 and 904,available for use in the ad hoc network 801 in geographic area A 806.The lower portion 903 of FIG. 9 shows that there are two spectrum bands,906 and 908, available for use in the ad hoc network 851 in geographicarea B 856. In the exemplary scenario shown in FIG. 9, the spectrumbands 904 and 908 are identical. In other words, part of the spectrumbands available in area A and area B (904 and 908) are the same, whilethe rest (902 and 906)

One reason that a different set of spectrum bands are available in adifferent area is that a spectrum band may have been allocated to otherservices in some geographic area but can be made available in anotherarea. When a wireless terminal moves into area A or area B, the wirelessterminal needs to first figure out which spectrum bands are availablefor use, so that the wireless terminal does not cause interference ordisruption to existing services.

To help the wireless terminal to figure out the spectrum availability ina given area, in accordance with a feature of some embodiments, aspecial transmitter transmits a system beacon signal in each of thespectrum bands that are available for use in the vicinity of thegeographical area in which the special transmitter is located. Thebeacon signal is a special signal that occupies a small fraction of thetotal minimum transmission units in the available spectrum. In someembodiments, the beacon symbols of the beacon signal occupy no more than0.1% of the total minimum transmission units in the available spectrumair link resource. A minimum transmission unit is the minimum unit ofresource to use for communication. In some exemplary frequency divisionmultiplexing systems, e.g., some OFDM systems, a minimum transmissionunit is a single tone over a symbol transmission period, sometimesreferred to as an OFDM tone-symbol. In addition, the transmission powerof the beacon symbols per minimum transmission unit is much higher,e.g., in some embodiments at least 10 dB higher, than the averagetransmission power of data and control signals per minimum transmissionunit when the transmitter is in an ordinary data session. In some suchembodiments, the transmission power of the beacon signal's beaconsymbols per minimum transmission unit is at least 16 dBs higher than theaverage transmission power of data and control signals per minimumtransmission unit when the transmitter is in an ordinary data session.

Drawing 1000 of FIG. 10 illustrates exemplary system beacon signalstransmitted in exemplary ad hoc networks (801, 851) in two differentgeographic areas (806, 856), respectively. The upper portion 1002illustrates the system beacon signal transmitted by the specialtransmitter 808 in area A 806 and the lower portion 1004 illustrates thesystem beacon signal transmitted by the special transmitter 858 in areaB 856.

In either the upper or the lower portion (1002, 1004), the horizontalaxis 1006 represents frequency and the vertical axis 1008 representstime.

Recall from FIG. 9 that spectrum bands 902 and 904 are available in areaA 806. The upper portion 1002 of FIG. 10 shows that the specialtransmitter 808 transmits the system beacon signal burst 1010 includingbeacon symbol(s) 1012 at time t1 1014 in spectrum band 902, andtransmits the system beacon signal burst 1016 including beacon symbol(s)1018 at time t2 1020 in spectrum band 904. The transmitter 808 thenrepeats the above procedure and transmits the system beacon signal burst1022 including beacon symbol(s) 1024 at time t3 1026 in spectrum band902 and transmits the system beacon signal burst 1028 including beaconsymbol(s) 1030 at time t4 1032 in spectrum band 904, and so on. In someembodiments, the beacon signal bursts 1010 and 1022 are identical, e.g.,the beacon symbols occupy the same positions in a beacon burst. In someembodiments, the beacon signal bursts 1010, 1022 vary, e.g., thepositions of the beacon symbols(s) change in accordance with apredetermined hopping sequence being implemented by beacon transmitter808. In some the beacon signal bursts 1016 and 1028 are identical. Insome embodiments the beacon signal bursts 1016 and 1028 vary, e.g., inaccordance with a predetermined hopping sequence being implemented bybeacon transmitter 808. In some embodiments, the beacon signal bursts1010 and 1016 are similar, e.g., the beacon symbols occupy the samerelative positions in the beacon burst.

Recall from FIG. 9 that spectrum bands 906 and 908 are available in areaB 856. The lower portion 1004 of FIG. 10 shows that the specialtransmitter 858 transmits the system beacon signal burst 1034 includingbeacon symbol(s) 1036 at time t5 1038 in spectrum band 906 and transmitsthe system beacon signal burst 1040 including beacon symbol(s) 1042 attime t6 1044 in spectrum band 908. The transmitter 858 then repeats theabove procedure and transmits the system beacon signal burst 1046including beacon symbol(s) 1048 at time t7 1050 in spectrum band 906 andtransmits the system beacon signal burst 1052 including beacon symbol(s)1054 at time t8 1056 in spectrum band 908, and so on.

In an exemplary embodiment, at a given time, a special transmittertransmits at most one beacon signal burst in a spectrum band. Thespecial transmitter hops across each of the available spectrum bands,successively from one spectrum band to another, and transmits the beaconsignal burst in each band at a given time. For example, in theembodiment shown in FIG. 10, times t1 1014, t2 1020, t3 1026, t4 1032 donot overlap with each other. However, it is also possible that in otherembodiments the transmitter may, and sometimes does, simultaneouslytransmit multiple beacon signals, each in a different spectrum band.

In the example of drawing 1000 of FIG. 10, with respect to thetransmitter 808 in area A, t4>t3>t2>t1, and with respect to thetransmitter 858 in area B, t8>t7>t6>t5. However, the drawing does notintend to show that a timing relationship between t5 and t4 exists suchthat t5 is necessarily greater than t4. For example, the range of timeincluding (t1, t2, t3, t4) and the range of time including (t5, t6, t7,t8) may, and sometimes does, at least partially overlap. In someembodiments, the two transmitters (808, 858) operate independently fromone another and are not intentionally timing synchronized. In someembodiments, the two transmitters (808, 858) have timing structureswhich are coordinated, e.g., synchronized with respect to one another.

FIG. 11 provides a detailed illustration of an exemplary wirelessterminal 1100 implemented in accordance with the present invention. Theexemplary terminal 1100, depicted in FIG. 11, is a detailedrepresentation of an apparatus that may be used as any one of terminals102 and 104 depicted in FIG. 1. In the FIG. 11 embodiment, the wirelessterminal 1100 includes a processor 1104, a wireless communicationinterface module 1130, a user input/output interface 1140 and memory1110 coupled together by bus 1106. Accordingly, via bus 1106 the variouscomponents of the wireless terminal 1100 can exchange information,signals and data. The components 1104, 1106, 1110, 1130, 1140 of thewireless terminal 1100 are located inside a housing 1102.

The wireless communication interface 1130 provides a mechanism by whichthe internal components of the wireless terminal 1100 can send andreceive signals to/from external devices and another terminal. Thewireless communication interface 1130 includes, e.g., a receiver module1132 and a transmitter module 1134, which are connected with a duplexer1138 with an antenna 1136 used for coupling the wireless terminal 1100to other terminals, e.g., via wireless communications channels.

The exemplary wireless terminal 1100 also includes a user input device1142, e.g., keypad, and a user output device 1144, e.g., display, whichare coupled to bus 1106 via the user input/output interface 1140. Thus,user input/output devices 1142, 1144 can exchange information, signalsand data with other components of the terminal 1100 via userinput/output interface 1140 and bus 1106. The user input/outputinterface 1140 and associated devices 1142, 1144 provide a mechanism bywhich a user can operate the wireless terminal 1100 to accomplishvarious tasks. In particular, the user input device 1142 and user outputdevice 1144 provide the functionality that allows a user to control thewireless terminal 1100 and applications, e.g., modules, programs,routines and/or functions, that execute in the memory 1110 of thewireless terminal 1100.

The processor 1104 under control of various modules, e.g., routines,included in memory 1110 controls operation of the wireless terminal 1100to perform various signaling and processing. The modules included inmemory 1110 are executed on startup or as called by other modules.Modules may exchange data, information, and signals when executed.Modules may also share data and information when executed. In the FIG.11 embodiment, the memory 1110 of wireless terminal 1100 includes asignaling/control module 1112 and signaling/control data 1114.

The signaling/control module 1112 controls processing relating toreceiving and sending signals, e.g., messages, for management of stateinformation storage, retrieval, and processing. Signaling/control data1114 includes state information, e.g., parameters, status and/or otherinformation relating to operation of the wireless terminal. Inparticular, the signaling/control data 1114 includes variousconfiguration information 1116, e.g., the page monitoring interval, thefrequency location of infrastructure spectrum hand andnon-infrastructure spectrum band, the timing and/or frequency referenceinformation of the beacon signal received from the infrastructure basestation, and the power relationship between the beacon signal and thedata/control traffic channel. The module 1112 may, and sometimes does,access and/or modify the data 1114, e.g., update the configurationinformation 1116. The module 1112 also includes a module 1113 forreceiving system info and timing info on non-infrastructure band frominfrastructure base station; module 1115 for using system and timinginfo in non-infrastructure band; module 1117 for suspending session innon-infrastructure band and monitoring pages in infrastructure band; andmodule 1119 for predicting signal quality of a data session fromreceived beacon signal power from a transmitter.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is aflowchart 1200 of an exemplary method of operating a wireless terminalto communicate with another communications device in accordance withvarious embodiments. Operation starts in step 1202, where the wirelessterminal is powered on and initialized and proceeds to step 1204. Instep 1204, the wireless terminal receives a first signal from a firstcommunications band, said first signal being from a first communicationsdevice which broadcasts on a recurring basis, said first communicationsdevice and said another communications device being differentcommunications devices. Operation proceeds from step 1204 to step 1206.

In step 1206, the wireless terminal determines, based on the firstsignal, a first time interval to be used for transmitting a secondsignal to said another communications device. Then, in step 1208, thewireless terminal determines based on the first signal a second timeinterval to be used for receiving signals from devices other than thefirst communications device. Operation proceeds from step 120 to step1210.

In step 1210, the wireless terminal derives frequency information fromthe received first signal. Step 1210 includes sub-step 1211 in which thewireless terminal determines a second communications band based on thereceived first signal. Operation proceeds from step 1210 to step 1212 inwhich the wireless terminal derives a parameter form the received firstsignal. Operation proceeds from step 1212 to step 1214 in which thewireless terminal receives another signal from the first communicationsdevice, and then in step 1216 the wireless terminal drives a secondparameter from another signal received from said first communicationsdevice Operation proceeds from step 1216 to step 1218.

In step 1218, the wireless terminal determines at least one transmitfrequency to be used for transmitting said second signal from thederived frequency information. Operations proceed from step 1218 viaconnecting node A 1220 to step 1222 of FIG. 12B.

In step 1222, the wireless terminal generates a second signal as afunction of one of device identifier corresponding to said wirelessterminal and a user identifier corresponding to a user of said wirelessterminal. Then, in step 1224, the wireless communications devicetransmits said second signal to said another communications deviceduring said first time interval. Step 1224 includes sub-step 1225 inwhich the wireless terminal transmits said second signal into saidsecond communications band, which is different from said firstcommunications band. Operation proceeds from step 1224 to step 1226.

In step 1226, the wireless terminal determines at least one additionaltransit time as a function of said parameter derived from said firstsignal. Step 1226 includes sub-step 1227, in which the wireless terminaluses a time hopping function which uses said parameter and/or saidsecond parameter as input parameters. Operation proceeds from step 1226to step 1228.

In step 1228, the wireless terminal establishes a peer to peercommunications session with said another device using timingsynchronization information derived from said first signal. Then, instep 1230, the wireless terminal exchanges user data as part of saidpeer to peer communications session, said user data including at leastone of voice data, other audio data, image data, text data and filedata, said peer to peer communications session being conducted directlybetween said wireless terminal and said another device over a directairlink.

In some embodiments the first and second communications bands arenon-overlapping. In various embodiments, the first and secondcommunications bands are partially overlapping. In some embodiments, thesecond signal includes a beacon signal burst, e.g., an OFDM beaconsignal burst including at least one beacon symbol. In some embodiments,the second signal is a pseudo noise sequence signal transmitted over thefrequency spectrum of the second frequency band. In some embodimentsboth the first and second signals are OFDM signals. In some embodiments,both the first and second signals are CDMA signals. In some embodiments,both the first and second signals are GSM signals. In some embodiments,the first signal is a CDMA second signal is an OFDM signal. In someembodiments, the first signal is a CDMA signal and the second signal isan OFDM signal. In various embodiments, the first signal is a satellitebroadcast signal, e.g., a GPS signal, a timing reference signal, areference signal obtained from a geostationary satellite, a signal froma satellite TV and/or radio broadcast, etc., and the second signal is aterrestrial broadcast signal. The terrestrial broadcast signal is, e.g.,from a fixed position base station, from a fixed position specialtransmitter, e.g., a beacon transmitter, or from a movable transmittertemporarily stationed at a fixed site to provide a reference such as abeacon signal, to be available for use by mobile nodes in the vicinityfor a peer to peer network. In some embodiments, the first signal isreceived from a terrestrial cellular network and the wireless terminalis a mobile handset.

One exemplary embodiment will now be described corresponding toflowchart 1200 of FIG. 12. The wireless terminal is a first mobile node,and the another communications device is a second mobile node whichparticipates in a peer to peer communications session with the firstmobile node. The first communications device is a device such as a basestation, special beacon transmitter, satellite, etc., which providesreference information to be used by the wireless terminal and anothercommunications device. The first signal is an OFDM beacon signal burstincluding at least one beacon symbol, e.g., a high energy tone,transmitted into the first frequency band. The another signal is, e.g.,a non-beacon broadcast signal transmitted from the first communicationsdevice. Reference timing information is derived from the first signaland used in determining a time for the wireless terminal to receivebeacon signals from other wireless terminals, e.g., peers, and indetermining a time to transmit its own user beacon signal. The secondsignal is an OFDM user beacon signal burst including at least one beaconsymbol, which is generated as a function of an identifier associatedwith the wireless terminal or wireless terminal user. From the receivedfirst signal the wireless terminal derives the second communicationsband, which is the communications band to be used for peer to peercommunications, which includes transmit frequencies of the user beaconto be generated by the wireless terminal. In this embodiment, the firstand second communications bands are non-overlapping. Thus the wirelessterminal's user beacon and peer to peer user data are communicated intothe same band, the second communications band. First and secondparameters are input control parameters used in a time hopping sequenceassociated with user beacon signals generated and transmitted by thewireless terminal. For example, one of first and second parameters mayprovide an indication or notion of time and the other may provide anidentifier associated with the transmitter. The wireless terminal timehops the relative position of the beacon burst within a time window fromone beacon burst to the next, in accordance with the hopping sequenceusing the input control parameters.

FIG. 13 is a drawing of an exemplary wireless terminal 2300, e.g.,mobile node, implemented in accordance with various embodiments.Exemplary wireless terminal 2300 includes a receiver module 2302, atransmission module 2304, a coupling module 2303, a processor 2306, userI/O devices 2308, a power supply module 2310 and memory 2312 coupledtogether via a bus 2314 over which the various elements may interchangedata and information. Memory 2312 includes routines 2316 anddata/information 2318. The processor 2306, e.g., a CPU, executes theroutines and uses data/information 2318 in memory 2312 to control theoperation of the wireless terminal 2300 and implement methods.

Coupling module 2303, e.g., a duplex module, couples the receiver module2302 to antenna 2305 and the transmission module 2304 to antenna 2305.Power supply module 2312, which includes a battery 2311, is used topower up the various components of the wireless terminal. Power isdistributed from the power supply module 2310 to the various components(2302, 2303, 2304, 2306, 2308, 2312), via a power bus 2309. User I/Odevices 2308 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2308 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a peer to peer communications session.

Routines 2316 include a transmission interval timing determinationmodule 2320, a receive interval timing determination module 2322, atransmission band control module 2324, a peer to peer communicationsband determination module 2326, a second signal generation module 2328,an additional transmit time determination module 2330, a peer to peercommunications establishment module 2332, a peer to peer sessionmanagement module 2334, a frequency information recovery module 2336,and a transmission frequency determination module 2338. Data/information2318 includes a received 1st signal 2340, a determined first timeinterval 2342, 1st frequency band information 2358, a second signal2344, a determined 2nd time interval 2346, 2nd frequency bandinformation 2360, device identification information 2362, useridentification information 2364, time hopping function information 2348,a first time hopping function input parameter 2350, a second timehopping function input parameter 2352, a plurality of transmit timescorresponding to beacon burst transmissions (transmit time for beaconburst 1 2354, . . . , transmit time for beacon burst n 2356), conveyedfrequency information 2366, and peer to peer session information 2368.The peer to peer session information 2368 includes peer identificationinformation 2370, received user data 2372, user data to be transmitted2374, and transmit frequency information 2376.

Receiver module 2302, e.g., a receiver, receives a first signal from afirst communication band, said first signal being from a firstcommunications device which broadcasts on a recurring basis. The firstcommunications device is a different communications device than thecommunications device with which wireless terminal 2300 has acommunications session. Information representing the received 1st signal2340 is stored in memory 2312, and 1st frequency band information 2358identifies the frequency band to which the receiver module is tuned whenreceiving the 1st signal. The 1st signal is, e.g., a broadcast signalused to obtain a timing reference by the wireless terminal 2300.Receiver module 2302 also receives signals from other communicationdevices, e.g., a part of communications sessions such as peer to peercommunications sessions. Some of the received signals include user data2372. In some embodiments, receiver module 2302 supports a plurality ofsignaling technologies, e.g., the first signal which is used as areference may be and sometimes is a different technology than thetechnology used for peer to peer communications sessions.

Transmission module 2304, e.g., an OFDM transmitter, is used fortransmitting a second signal 2344 to a communications device, e.g., apeer wireless terminal, during a determined 1st time interval 2342. Insome embodiments, the second signal 2344 includes a beacon signal burst,e.g., an OFDM beacon signal burst including at least one beacon symbol.Transmission module 2304 also transmits user data 2344, as part of apeer to peer communications session using transmit frequency information2376.

Transmission interval timing determination module 2322 determines, basedon the received 2st signal 2340, a first time interval 2342 to be usedfor transmitting 2nd signal 2344, e.g., a WT 2300 beacon signal burst,to another communications device, e.g., a peer wireless terminal.Receive interval timing determination module 2322 determines, based onthe received 1st signal 2340, a 2nd time interval 2346 to be used forreceiving signals from devices other than the device which transmittedthe 1st signal. In some embodiments, the 2nd time interval is a timeinterval in which wireless terminal 2300 is to receive and monitor forbeacon signals from another communications device, e.g., peer wirelessterminal.

Transmission band control module 2324 controls the wireless terminal2300 to transmit the 2nd signal 2344, e.g., WTs 2300's beacon signalburst, in a second communications hand identified by 2nd frequency bandinformation 2360. In some embodiments, the 2nd frequency band isdifferent from the 1st frequency band. For example, the wirelessterminal 2300 receives a broadcast signal used for timingsynchronization in a 1st band and transmits its user beacon in a 2ndfrequency band, which is a different band.

Peer to peer communications band determination module 2326 determines,prior to transmitting the 2nd signal 2344 the 2nd communication bandbased on the 1st received communications signal 2340. Thus peer to peercommunications band determination module 2326 determines 2nd frequencyband information 2360. In some embodiments, the 1st and 2nd frequencybands are non-overlapping frequency bands. In some embodiments, the 1stand 2nd frequency bands are partially overlapping frequency bands.

Second signal generation module 2328, generates 2nd signal 2344, priorto transmitting the second signal as a function of one of a deviceidentifier 2362 corresponding to the wireless terminal and a useridentifier 2364 corresponding to a user of wireless terminal 23. In someembodiments, second signal generation module 2328 generates signalingincluding beacon signal bursts, e.g., OFDM beacon signal burstsincluding at least one beacon symbol. In some embodiments, the secondsignal is a pseudo noise sequence transmitted over the second frequencyband.

Additional transmit time determination module 2330 determines at leastone additional transmit time as a function of a parameter derived fromthe 1st signal, e.g., time hopping function input parameter 1 2350. Theadditional transmit time determination module 2330 uses a time hoppingfunction which uses parameter 2350 as an input. Time hopping functioninformation 2348 includes, e.g., information defining the time hoppingsequence. In some embodiments, the time hopping function uses a secondinput parameter 2352 derived from another signal received from thecommunications device which transmitted the 1st broadcast signal. Forexample, the another signal may be, and sometimes is, a non-beaconbroadcast signal communicating the 2nd input parameter. The anothersignal may be, and sometimes is, another beacon signal burst.

Peer to peer communications establishment module 2323 is used toestablish a peer to peer communications session with another device,e.g., a peer node, using timing synchronization information derived fromthe received 1st signal 2340.

Peer to peer session management module 2334 controls the exchange ofused data including at least one of voice data, text data, and imagedata, said peer to peer communications session being conducted directlybetween the wireless terminal and another device, e.g., peer wirelessterminal, over a direct air link.

Frequency information recovery module 2336 recovers conveyed frequencyinformation 2366 from the received 1st signal 2340, prior totransmitting the second signal 2344, deriving frequency information fromthe received 1st signal 2340. For example, the 1st signal conveyedinformation identifying the 2nd frequency band, the 2nd frequency bandto be used by wireless terminal 2300 for transmitting its user beaconsignal and for peer to peer user data communications.

Transmission frequency determination module 2338 determines at least onetransmit frequency to be used for transmitting the second signal fromderived frequency information. Information including in 2376 is anoutput of module 2338. Transmit information 2376 includes, e.g.,frequency band information and/or individual tone identificationinformation. In some embodiments, transmit frequency informationidentifies OFDM tones used to convey beacon symbols of beacon signalbursts to be transmitted by wireless terminal 2300. In some suchembodiments, beacon symbol tones are tone hopped from one burst toanother in a sequence of bursts in accordance with a tone hoppingsequence.

In some embodiments, both the first and second signals are OFDM signals.In some embodiments, the first signal is a GSM signal and the secondsignal is an OFDM signal. In some embodiments, the first signal is aCDMA signal and the second signal is an OFDM signal. In someembodiments, the first signal is a satellite broadcast signal isreceived from a terrestrial broadcast signal. In some embodiments, thefirst signal is received from a terrestrial cellular network and thewireless terminal is a mobile handset.

FIG. 14 is a drawing of a flowchart 1300 of an exemplary method ofoperating a wireless terminal which supports both peer to peercommunications and communications with a base station in accordance withvarious embodiments. Operation starts in step 1302, where the wirelessterminal is powered on and initialized and proceeds to step 1304. Instep 1304, the wireless terminal receives a first signal from a firstcommunications band, the first signal being from a base station.Operation proceeds from step 1304 to step 1306. In step 1306, thewireless terminal determines the frequency of a second communicationsband from the first signal, and in step 1308, the wireless terminaldetermines an interval of time during which the wireless terminal is tomonitor for a second signal in the second communications band, thedetermination of the time interval being based on informationcommunicated by the first signal, e.g., a time reference communicated.Operation proceeds from step 1308 to step 1310.

In step 1310, the wireless terminal determines from said first signallink the quality of a first link between said base station and saidwireless terminal, and in step 1312, the wireless terminal predicts afirst data throughput to the base station based on the first determinedlink quality. Step 1312 includes sub-step 1314, in which the wirelessterminal uses maximum transmission power information in the first linkquality determination. The maximum transmission power informationincludes, e.g., at least one of a government restriction on maximumtransmission power and device output capability. Operation proceeds fromstep 1312 to step 1316.

In step 1316, the wireless terminal monitors during said determined timeinterval to receive said second signal, and then in step 1318, thewireless terminal receives said second signal from the secondcommunications band, said second communications band being differentfrom the first communications band, said second signal being from a peerwireless terminal. In some embodiments, the first and second signal eachinclude at least one beacon signal burst.

Operation proceeds from step 1318 to step 1320. In step 1320, thewireless terminal predicts a second data throughput to the peer wirelessterminal based on the second determined link quality. Step 1320 includessub-step 1322 in which the wireless terminal uses maximum transmissionpower information in the second link quality determination. The maximumtransmission power information includes, e.g., at least one of agovernment restriction on maximum transmission power and device outputcapability. Operation proceeds from step 1320 to step 1324, in which thewireless terminal selects between said first and second links for acommunications session based on the determined quality of the first andsecond links Step 1324 includes alternative sub-steps 1326, 1328, and1330.

In alternative sub-step 1326, the wireless terminal selects the one ofthe first and second links having a higher data throughput. Inalternative sub-step 1328, the wireless terminal performs the selectionas a function of energy required to maintain said first and secondlinks, said selecting including selecting the one of the first andsecond links satisfying a link quality requirement and also requiringthe least amount of energy to maintain. In alternative sub-step 1330,the wireless terminal performs selection as a function of a lest costrouting determination that takes into consideration an economic costassociated with using individual ones of said first and second links.

FIG. 15 is a drawing of an exemplary wireless terminal 2400, e.g.,mobile node, implemented in accordance with various embodiments.Exemplary wireless terminal 2400 supports both peer to peercommunications and communications via a base station. Exemplary wirelessterminal 2400 includes a receiver module 2402, a transmitter module2404, a processor 2406, user I/O devices 2408, a memory 2410 coupledtogether via a bus 2412 over which the various elements may exchangedata and information. Memory 2410 includes routines 2414 anddata/information 2416. The processor 2406, e.g., a CPU, executes theroutines 2414 and uses the data/information 2416 in memory 2410 tocontrol the operation of the wireless terminal 2400 and implementmethods.

Receiver module 2402, e.g., an OFDM receiver, is coupled to receiveantenna 2403 via which the wireless terminal 2400 receives signals frombase stations and other wireless terminals. Transmitter module 2404,e.g., an OFDM transmitter, is coupled to transmit antenna 2405 via whichthe wireless terminal 2400 transmits signals to base stations and toother wireless terminals. In some embodiments, the same antenna is usedfor both the receiver and transmitter modules (2402, 2404).

User I/O devices 2408 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2408 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a communications session.

Routines 2414 include a communications routine 2418 and wirelessterminal control routines 2420. The communications routine 2418implements the various communications protocols used by the wirelessterminal 2400. The wireless terminal control routines 2420 include abase station link quality determination module 2422, a peer to peer linkquality determination module 2424, a link selection module 2426, abeacon burst processing module 2428, a user data recovery module 2430, afirst data throughput determination module 2432, a second datathroughput determination module 2434, a power requirement estimationmodule 2436, a routing cost determination module 2438, a frequency banddetermination module 2440, a monitor interval determination module 2242,and a peer to peer signal monitoring module 2444.

Data/information 2416 includes a received 1st signal 2446, 1st frequencyband information 2448, base station identification informationcorresponding to the base station which transmitted the 1st signal 2450,recovered 1st link information 2452, predicted 1st link data throughput2454, estimated amount of energy required to maintain 1st link 2456,routing cost determination associated with 1st link 2458, determined 1stlink quality 2460, received 2nd signal 2462, 2nd frequency bandinformation 2464, peer wireless terminal identification informationcorresponding to the peer wireless terminal which transmitted the 2ndsignal 2465, recovered 2nd link information 2466, predicated 2nd linkdata throughput 2468, estimated amount of energy required to maintain2nd link 2470, routing cost determination associated with 2nd link 2472,determined 2nd link quality 2474, selected link information 2476,recovered user data 2478, stored maximum transmission power information2480, stored link quality requirement information 2486, and determinedinterval of time to monitor for second signals 2488. Stored maximumtransmission power information 2480 includes government restrictioninformation 2482 and device output capability information 2484.

Receiver module 2402 receives a 1st signal from a 1st communicationband, the first signal being from a base station. Received 1st signal2446 includes information representing the 1st signal which was receivedin the band identified by 1st frequency band information 2448 and wastransmitted by the base station identified in information 2450. Receivermodule 2402 also receives a second signal from a second communicationsband which is different from the first communications band, said secondsignal being from a peer wireless terminal. Received 2nd signal 2462includes information representing the 2nd signal which was received inthe band identified by 2nd frequency band information 2464 and wastransmitted by the peer wireless terminal identified in information2465. In some embodiments, the first and second signals each include atleast one beacon signal burst, e.g., an OFDM beacon signal burstincluding at least one beacon symbol.

Base station link quality determination module 2422 determines, from thefirst signal, link quality of a first link between a base station whichtransmitted the first signal and the wireless terminal 2400, anddetermined 1st link quality 2460 is an output of module 2422. Peer topeer link quality determination module 2424 determines, from the secondsignal, link quality of a second link between a peer wireless terminalwhich transmitted the second signal and the wireless terminal 2400, anddetermined 2nd link quality 2474 is an output of module 2424.

Link selection module 2462 selects between 1st and 2nd links, for acommunications session, based on the determined quality of the first andsecond links. Determined 1st link quality 2460 and determined 2nd linkquality 2474 are inputs to link selection module 2426 and selected linkinformation 2476 is an output of link selection module 2426 whichidentifies the selected link.

Beacon burst processing module 2428 recovers link information frombeacon signal bursts (recovered 1st link information 2452 correspondingto 1st signal, recovered 2nd link information 2466 corresponding to 2ndsignal). User data recovery module 2430 recovers user data 2478 fromnon-beacon signals used to communicate user data as part of acommunications session. At some times the recovered user data 2478 isfrom a peer to peer communication session, while at other times therecovered user data is from a communications session in which the userdata is relayed through a base station serving as an access node.

First data throughput determination module 2432 predicts a first datathroughput 2454 to the base station based on the first determined linkquality 2460. Second data throughput determination module 2434 predictsa second data throughput 2468 to the peer wireless terminal based on thesecond determined link quality 2474. Link selection module 2426 includesa throughput based selection module for selecting the one of the firstand second links having the higher data throughput. First datathroughput determination module 2432 uses the stored maximumtransmission power information 2480 in predicting the first datathroughput 2454. Second data throughput determination module 2434 usesthe stored maximum transmission power information 2480 in predicting thesecond data throughput 2468.

Power requirement estimation module 2436 estimates the amount of energyrequired to maintain the 1st and 2nd links (estimated amount of energyrequired to maintain 1st link 2456, estimated amount of energy requiredto maintain 2nd link 2470). Link selection module 2426 also performsselection between first and second links for a communications session asa function of energy required to maintain first and second links, saidselecting including selecting the one of the 1st and 2nd linkssatisfying a link quality requirement 2486 and also requiring the leastamount of energy to maintain.

Routing cost determination module 2438 performs a routing costdetermination that takes into consideration economic costs associatedwith using individual ones of the first and second links. Routing costdetermination associated with 1st link 2458 and routing costdetermination associated with 2nd link 2472 are outputs of module 2438.Link selection module 2426 also performs selection between first andsecond links as a function of least cost routing determination, e.g.,using info (2458, 2472) that takes into consideration economic costsassociated with individual ones of the first and second links.

Frequency band determination module 2440 determines, prior to receivingthe second signal, the frequency band of the second signal from thefirst signal. Thus a base station identifies the frequency band to beused for peer to peer communications in its vicinity. Monitor intervaldetermination module 2442 determines an interval of time during whichsaid wireless terminal 2400 is to monitor for second signals 2488, e.g.,a time interval for wireless terminal 2400 to search for user beaconsignals from peer nodes. Peer to peer signal monitoring module 2444monitors for a signal from a peer wireless terminal during the intervalidentified to receive second signals, e.g., peer to peer signalmonitoring module 2444 monitors for user beacon signal bursts from peernodes.

In some embodiments, the selection module 2426 changes selectioncriteria and/or re-weights selection criteria as a function of basestation identification information, peer identification information,priority information, type of information anticipated to becommunicated, wireless terminal 2400 current conditions, and/or latencyrequirements. For example, selection module 2426, in some embodiments,heavily weights the selection as a function of energy requirements, whena low battery power condition is detected in wireless terminal 2400. Asanother example, selection module 2426 heavily weights the selectionbased on predicted data throughput when a large amount of time criticaldata is anticipated to be communicated.

FIG. 16 is a drawing of a flowchart 1400 of an exemplary method ofoperating a base station in accordance with various embodiments.Operation starts in step 1402, where the base station is powered on andinitialized and proceeds to step 1404. In step 1404, the base stationtransmits a beacon signal, said beacon signal including at least onebeacon signal burst, said beacon signal conveying information about peerto peer frequency band, e.g., a peer to peer frequency band which isavailable for use in the vicinity of the base station. Step 1404includes sub-step 1406. In sub-step 1406, the base station transmits thebeacon signal into a first communications band, said beacon signalconveyed information indicating a second frequency band which is used assaid peer to peer frequency band, said second frequency band beingdifferent from said first frequency band. Operation proceeds from step1404 to step 1408.

In step 1408, the base station transmits a second beacon signal into thefirst communications band, said second beacon signal providing timingsynchronization information to a plurality of wireless terminals usingthe base station as an access node. Operation proceeds from step 1408 tostep 1410.

In step 1410, the base station receives data from at least some of saidplurality of wireless terminals using said base station as an accessnode for communication through said access node, and in step 1412, thebase station transmits user data to at least some of said plurality ofwireless terminals using said base station as an access node using thefirst frequency band. Operation proceeds from step 1412 to step 1404.

In some embodiments, the first frequency band is used in a time divisionmultiplexed manner, and said step of receiving data (1410) receives datain the first communications band during a first time period and saidstep of transmitting user data into the first frequency band (1412) isperformed during a second time period which is different from said firsttime period. In some other embodiments, the base station uses the firstfrequency band for transmitting signals including said beacon signal,said second beacon signal and said user data signals, while a thirdcommunications band is used for receiving user data signals fromwireless terminals using the base station as an access point. In somesuch embodiments, the first, second and third communications bands aredifferent and non-overlapping. In some such embodiments, the basestation transmits and receives user data concurrently.

In some embodiments, the average base station transmitted power into thesecond communications band over a 1 minute tie period is less than1/1000 the average base station transmitted power into the firstfrequency band over the same 1 minute interval. In some suchembodiments, the base station does not transmit any power into thesecond frequency band.

In another embodiment, which is a variation of embodiments describedwith respect to flowchart 1400, the base station transmits its accessnode beacon signal and user data into the first frequency band, andtransmits a beacon signal for peer to peer communications into thesecond frequency band, the second frequency band being used for peer topeer communications, but the base station does not transmit any userdata into the second frequency band. In some such embodiments, theaverage base station transmitted power into the second communicationsband over a 1 minute time period is less than 1/1000 the average basestation transmitted power into the first frequency band over the same 1minute interval.

In still another embodiment, which is a variation with respect toflowchart 1400, the base station transmits both its access node beaconsignal and its peer to peer node beacon signal in a first frequency bandused for beacon signals. In addition, the base station transmits userdata intended for wireless terminals using the base station as an accessnode into a second frequency band; and the base station refrains fromtransmitting user data into a third frequency band which is utilized forpeer to peer communications, wherein said first, second and thirdcommunications bands are non-overlapping.

FIG. 17 is a drawing of an exemplary base station 2500 in accordancewith various embodiments. Exemplary base station 2500 includes areceiver module 2502, with associated antenna 2501, a transmissionmodule, with associated transmitter antenna 2503, a processor 2506, andI/O interface 2508, and memory 2510 coupled together via a bus 2412 overwhich the various elements interchange data and information. Memoryincludes routines 2514 and uses the data/information processor 2506,e.g., a CPU, executes the routines 1514 and uses the data/information2516 in memory 2510 to control the operation of the base station 2500and implement methods, e.g., the method of FIG. 16.

Routines 2514 include a beacon signal generation module 2518, afrequency band control module 2520, a user data transmission controlmodule 2522, a transmission power control module 2524, and an accessnode beacon signal generation module 2526.

Data/information 2516 includes stored peer to peer beacon signalcharacteristic information 2528, stored access node beacon signalcharacteristic information 2534, peer to peer beacon signal transmissionband information 2556, access node beacon signal transmission bandinformation 2558, peer to peer communications band information 2560,base station access node band information 2562, timing information 2564,transmission power information 2566, and wireless terminaldata/information 2540 corresponding to wireless terminals using the basestation 2500 as an access node.

Stored peer to peer beacon signal characteristic information 2528includes one or more sets of beacon burst information (beacon burst 1information 2350, . . . , beacon burst N information 2532). Storedaccess node beacon signal characteristic information 2534 includes oneor more sets of beacon burst information (beacon burst 1 information2536, . . . , beacon burst N information 2538).

WTs data/information 2540 corresponding to WTs using the base station asan access node includes a plurality of sets of information (WT 1data/information 2542, . . . , WT n data/information 2544). WT 1data/information 2542 includes received user data 2546, user data to betransmitted 2548, a base station assigned wireless terminal identifier2550, state information 2552, and communications session information2554.

Receiver module 2502, e.g., and OFDM receiver, receives uplink signalsfrom wireless terminals using the base station 2500 as an access node.The received signals include user data signals, e.g., traffic channelsignals, from a plurality of wireless terminals using base station 2500as an access node for communication through the access node. Receiveduser data 2546 corresponding to WT 1 represents user data obtained fromreceived signals from one exemplary wireless terminal using base station2500 as an access node.

Transmitter module 2504, e.g., an OFDM transmitter, transmits signals towireless terminals in its vicinity. The transmitted signals include agenerated beacon signal intended to support peer to peer communicationsin its vicinity. The generated beacon signal includes at least onebeacon signal burst and conveys information about a peer to peerfrequency band. The transmitted signals also include a generated secondbeacon signal intended to support access node operations, the generatedsecond beacon signal providing timing synchronization information to aplurality of wireless terminals using the base station as an accessnode. In some embodiments, the generated beacon signal conveying peer topeer frequency band information and the generated second beacon signalcommunicating access node timing synchronization information aretransmitted into the same frequency band. The transmitter 2504 alsotransmits control data and user data to wireless terminals using thebase station as an attachment point. User data to be transmitted 2548,corresponding to wireless terminal 1, is an example of user data that istransmitted by the base station 2500, e.g., in downlink traffic channelsegments, to a wireless terminal using the base station as an accessnode. User data includes, e.g., voice, image, text, and/or file data.

In some embodiments, receiving data includes receiving data fromwireless terminals using the base station as an access node in a firstfrequency band during a first period of time and transmitting user datainto the first frequency band is performed during a second period oftime which is different from the first period of time, said frequencyband being used in a time division multiplexed manner. Timinginformation 2564, in some embodiments, identifies first and secondperiods of time. In various embodiments, the base station does nottransmit or receive user data into a second frequency band designated tobe used for peer to peer communications.

I/O interface 2508 couples the base station 2500 to other network nodes,e.g., other base station, AAA node, home agent nodes, etc. and/or theInternet. I/O interface 2508, by coupling base station 2500 to abackhaul network allows a wireless terminal using base station 2500 asits point of network attachment to participate in a communicationssession with another wireless terminal using a different base station asits point of network attachment.

Beacon signal generation module 2518 generates a beacon signal, saidbeacon signal including at least one beacon signal burst, said beaconsignal burst conveying information about a peer to peer frequency band,e.g., identifying the peer to peer frequency band. Stored peer to peerbeacon signal characteristic information 2528 is used by beacon signalgeneration module 2518 in generating the beacon signal. In someembodiments, the generated beacon signal by module 2518 conveys peer topeer communications band information 2560.

Frequency band control module 2520 controls transmission of the beaconsignal generated by module 2518 into a first communications band, thebeacon signal conveying information indicating a second frequency bandwhich is used as the peer to peer frequency band, said second frequencyband being different from the first frequency band. In some suchembodiments, the first frequency band is the frequency band identifiedby peer to peer beacon signal transmission band information 2556 and thesecond frequency band identified by peer to peer communication bandinformation 2560.

User data transmission control module 2522 controls transmission of userdata to multiple ones of the plurality of wireless terminals using thebase station as an access point using a transmission band identified bythe base station access node information. In some embodiments, the bandused for transmission of user data to a wireless terminal using the basestation as a point of network attachment is the same as the first bandwhich is the band into which the generated beacon signal for peer topeer communications is transmitted.

Transmission power control module 2524 controls transmission power intothe second frequency band, which is the frequency band used for peer topeer communications, to keep the base station average transmitted powerinto the second frequency band over a 1 minute time period less than1/1000 the average transmitted power transmitted into the firstfrequency band, e.g., the frequency band used for the beacon signal andaccess node related downlink signaling including user data. In someembodiments, the base station 2500 does not transmit into the secondfrequency band, which is used for peer to peer communications.

Access node beacon signal generation module 2526 uses thedata/information 2516 including the access node beacon signalcharacteristic information 2534 to generate a second beacon signal, thesecond beacon signal providing timing synchronization information to theplurality of wireless terminals using the base station 2500 as an accessnode.

In some embodiments, (i) the band into which the beacon signalidentifying the peer band is transmitted, (ii) the band into which thebeacon signal used for wireless terminal timing synchronization withregard to access node operations is transmitted, and (iii) the band usedfor downlink access node signaling to wireless terminals is the sameband. In some such embodiments, the ban used for peer to peercommunications is a different, non-overlapping band. Thus information2556, 2558, and 2562, in some embodiments identify the same band, whileinformation 2560 identifies a different band.

FIG. 18 is a drawing of an exemplary beacon signal transmissionapparatus 1500 in accordance with various embodiments. Exemplary beaconsignal transmission apparatus 1500 is a free standing device and doesnot include any transmitter used to transmit user data to an individualuser device. Exemplary beacon signal transmission apparatus 1500includes a receiver module 1502, a beacon signal transmitter 1504, aprocessor 1506, a solar power supply by bus 1507. Memory 1512 includesroutines 1516 and data/information 1518. The processor 1506, e.g., aCPU, executes the routines 1516 and uses the data/information 1518 inmemory 1512 to control the apparatus 1500 and implement methods.

Routines 1516 include a beacon signal transmission control module 1520,a beacon signal generation module 1522, a receiver control module 1524and a received broadcast signal information recovery module 1526.Data/information 1518 includes stored beacon signal characteristicinformation 1532, and beacon transmitter identification information1534. Stored beacon signal characteristic information 1528 includes oneor more sets of beacon burst information (beacon burst 1 information1536, . . . , beacon burst N information 1538), beacon symbolinformation 1540, and power information 1542. Beacon burst 1 information1536 includes information identifying beacon transmission units carryinga beacon symbol 1544 and beacon burst duration information 1546. Storedbeacon signal control information 1530 includes beacon burst/frequencyband/timing relationship information 1552.

Receiver module 1502 is coupled to receive antenna 1501 via which theapparatus 1500 receives signals, e.g., a signal used for timingsynchronization purposes. In some embodiments, the receiver is an OFDMreceiver. In some embodiments, the signals, and, e.g., depending uponthe area of deployment a different type of signal is received andutilized as a reference source. In some such embodiments, the receivercontrol module 1524 follows a predetermined ordered sequence whendetermining reference signal search protocol.

Receiver 1502, under the control of receiver control module 1524,receives a broadcast signal and received broadcast signal informationrecovery module 1526 recovers received broadcast signal information 1532from the received broadcast signal including timing information 1552,e.g., a time reference.

Beacon signal transmitter 1504, e.g., an OFDM transmitter, is coupled totransmit antennas (sector 1 antenna 1503, . . . , sector N antenna 1505)via which the apparatus 1500 transmits beacon signal bursts which areused to support a peer-peer communications network. Beacon signaltransmitter 1504 transmits a sequence of beacon signal bursts, eachbeacon signal burst including at least one beacon symbol. Beacon signaltransmission control module 1520 uses the data/information 1518 inmemory 1512 including stored beacon signal control information 1530 andtiming information 1552 to control the transmission of beacon burstsignals, e.g., controlling beacon signal burst transmission timing as afunction of the received broadcast signal which was detected andprocessed. Beacon signal transmission control module 1520 uses thedata/information 1518 including timing information 1552 and beaconburst/frequency band/timing relationship information 1548 to control thebeacon transmitter 1504 to transmit beacon signal bursts into differentfrequency bands at different times. Beacon signal transmission controlmodule 1520 uses the data/information 1518 including timing information1552 and beacon burst/sector/timing relationship information 1548 tocontrol the beacon transmitter 1504 to transmit beacon signal burstsinto sectors at different times. In some such embodiments, the beaconsignal transmission control module 1520 controls the beacon signaltransmitter 1504 to transmit into at most one sector at a time.

Solar power supply module 1508 includes solar cell 1509 for convertingsolar energy to electrical energy such that apparatus 1500 can be, andsometimes is solar powered. Power supply module 1510 includes battery1511 for storing energy such that apparatus can be, and sometimes ispowered by battery 1511. Some embodiments include a battery power supply1511, but do not include a solar power supply module 1508, e.g., withthe batteries being replaced and/or recharged periodically. In someembodiment, apparatus 1500 is expected to operate for the duration ofthe battery life and then be discarded or refitted with a replacementbattery. In some embodiments, the beacons signal transmission apparatus1500 is independently powered, e.g., operating from a portable gasoline,diesel, kerosene, propane, natural gas, and/or hydrogen based, generatorand/or fuel cell. Embodiments using solar, battery and/or otherindependent energy sources are advantageous in remote sites, where alocal power grid may be unavailable and/or in areas where a power gridis unreliable. In various embodiments, beacon signal transmission poweris coupled to a power grid for receiving power.

Beacon signal generation module 1522 uses the data/information includingstored beacons signal characteristic information 1528 and/or beacontransmitter identification information 1534 to generate a sequence ofbeacon signal bursts, each beacon signal bust including at least onebeacon symbol, the beacon signal burst intended to be used to supportpeer communications. Information identifying beacon transmission unitscarrying a beacon symbol 1544 include, e.g., information identifying asubset of OFDM tone-symbols designated to carry a high power beaconsymbol in a set of OFDM tone-symbols of beacon burst 1. Beacon burstsymbol information 1540 includes information defining a beacon symbol,e.g., a modulation symbol value, while power information 1542 includestransmission power level information associated with the beacon signal.In some embodiments, each of the beacon symbols is controlled to betransmitted at the same transmission power level. In some embodiments,each of the beacon symbols corresponding to a given sector and a givenfrequency band are controlled to be transmitted at the same transmissionpower level, with at least some beacon symbols corresponding todifferent sectors and/or frequency bands are transmitted at differentpower levels.

FIG. 19 is a drawing of a flowchart 2600 of an exemplary method ofoperating a beacon signal transmitter device in accordance with variousembodiments. The beacon signal transmitter device is, e.g., a freestanding device, and the beacon signal transmitter device does notinclude any transmitter used to transmit user data to an individual userdevice, e.g., wireless terminal. In various embodiments, the beaconsignal transmitter device includes an OFDM beacon signal transmitter fortransmitting OFDM beacon signal bursts, each beacon signal burstincluding at least one relatively high power OFDM beacon symbol, e.g.,with respect to the transmission power levels of data symbolstransmitted by wireless terminals communicating in a peer to peercommunications session in the local region being serviced by the beaconsignal transmitter device.

Operation starts in step 2602, where the beacon signal transmitterdevice is powered on and initialized. Operation proceeds from start step2602 and proceeds to step 2604. In step 2604, the beacon signaltransmitter device scans for different types of broadcast signals thatcan be used as timing reference signals. In some embodiments, thescanning is performed based on a predetermined sequence based on atleast some geographic location information. Then, in step 2606, thebeacon signal transmitter device receives a broadcast signal, and instep 2608 determines a signal burst transmission timing as a function ofthe received broadcast signal. In some embodiments, the receiver is areceiver which includes at least one of a GPS receiver, a GSM receiver,and a CDMA receiver. Operation proceeds from step 2608 to step 2610.

In step 2610, the beacon signal transmitter device is operated totransmit a sequence of beacon signal bursts, each beacon signal burstincluding at least one beacon symbol. Step 2610 includes sub-steps 2612,2614, 2616, 2618, 2620, and 2622. In sub-step 2612, the deacon signaltransmitter device's transmitter is powered from one of: a battery powersource, a solar power source, and a power source which is independent ofa commercial power grid.

In sub-step 2614, the beacon signal transmitter device compares currenttiming information to predetermined schedule information. Operationproceeds from sub-step 2614 to sub-step 2616, in which the beacon signaltransmitter device determines if it is time to transmit a beacon signalburst or bursts. If it is determined in sub-step 2616, that it is nottime to transmit a beacon signal burst, then operation proceeds back tostep 2614 for additional comparison of timing information. However, ifit is determined in sub-step 2616, that the beacon signal transmitterdevice is scheduled to transmit a beacon signal burst(s), then operationproceeds to sub-step 2618, where the device determines the frequencyband or bands into which the beacon signal burst(s) are to betransmitted. Operation proceeds from sub-step 2618 to sub-step 2620, inwhich the device determines the sector or sectors into which the beaconsignal burst or bursts are to be transmitted. Then, in sub-step 2622,the beacon signal transmitter device transmits the scheduled beaconsignal burst or bursts into the determined frequency band or bands intothe determined sector or sectors. Operation proceeds from sub-step 2622back to sub-step 2614 for additional time comparisons.

In various embodiments, the beacon signal transmitter device uses storedcontrol information to determine a plurality of frequency bands intowhich the beacon signal bursts are to be transmitted and the time atwhich the transmission of the beacon signal bursts are to occur. In someembodiments, the beacon signal transmitter device controls itstransmitter to transmit beacon signal burst into different frequencybands at different times. In some embodiments, the beacon signaltransmitter device controls its transmitter to use a multi-sectorantenna and to transmit beacon signal bursts into different sectors atdifferent times. In one such embodiment, the beacon signal transmitterdevice controls its transmitter to transmit into at most one sector at atime. In some embodiments, the beacon signal transmitter device controlsits transmitter to transmit into at most one frequency band at a time.

In various embodiments, the beacon signal transmitter controls itstransmitter to transmit into multiple frequency bands in each ofmultiple sectors of a cell. In some embodiments, the beacon signaltransmitter is controlled to transmit into at most one frequency hand ofone sector at a given time at which beacon signal bursts aretransmitted.

In some embodiments, described with respect to flowchart 2600, thebeacon signal transmitter device obtains an external reference from areceived broadcast signal. In some embodiments, the beacon signaltransmitter does not include s receiver and does not receive a referencesignal. For example, the beacon signal transmitter device transmits itsbeacon signal bursts in accordance with stored schedule informationcorresponding to a recurring schedule, and the beacon signal transmitterdevice's timing is free running and not coordinated with any otherbeacon signal transmitter device.

FIG. 20 is a drawing of a flowchart 1600 of an exemplary method ofoperating a base station in accordance with various embodiments. Theexemplary base station switches between infrastructure spectrum use andpeer to spectrum use. Thus at different times spectrum, e.g., afrequency band, in the vicinity of the base station is used fordifferent purposes. Operation starts in step 1602, where the basestation is powered on and initialized and proceeds to step 1604 andconnecting nodes A 1606, B 1608, C 1610 and D 1612.

In step 1604, the base station sets its mode to a second mode, e.g., anaccess mode operation mode with respect to a first frequency band. Inthis particular exemplary embodiment, the access mode with respect tothe first frequency band is the start-up default mode. In otherembodiments, the peer to peer mode of operation is the start-up defaultmode, and the base station starts up in a mode in which the firstfrequency band is designated to be used for peer to peer communications.Operation proceeds from step 1604 to steps 1614 and step 1616.

In step 1614, the base station transmits a second broadcast signalduring a second period of time conveying information that a firstfrequency band is be used as a non-peer to peer frequency band during asecond period of time. In step 1616, during the second period of time,the base station operates as a network access point to relay informationreceived over an airlink from a first communications device via acommunications network to a second communications device. Operationproceeds from step 1614 and step 1616 to step 1618.

Returning to connecting node A 1606, operation proceeds via connectingnode A 1606 to step 1628, where the base station monitors communicationsactivity level during the second mode of operation. Operation proceedsfrom step 1628 to step 1630, in which the base station checks whetherthe activity is below a predetermined threshold. If the level ofactivity is below a predetermined threshold, then operation proceeds tostep 1632, where the activity level information 1636 is updated toindicate a low level of activity, e.g., corresponding to a level inwhich the mode is to be switched in response to the determined lowlevel. If the activity level is not below the threshold, then operationproceeds from step 1630 to step 1634 in which the base station updatesthe activity level information 1636 to indicate that the threshold isabove the mode switch threshold, e.g., the base station should remain inthe second mode based on the current level of activity. In someembodiments, the predetermined threshold corresponds to one wirelessterminal currently using the base station as a network attachment point.In some embodiments, the predetermined threshold corresponds to onewireless terminal currently using the base station as a networkattachment point and communicating at least some user data via the basestation from and/or to that wireless terminal. Operation proceeds fromstep 1632 or step 1634 to step 1628 for additional monitoring.

Returning to connecting node B 1608, operation proceeds via connectingnode B 1608 to step 1638, where the base station monitors for signalsfrom wireless terminals, while in a first mode of operation, indicatingthat a wireless terminal is seeking to use the base station as an accesspoint. Then, in step 1640, the base station checks if a signal wasdetected in step 1638. If a signal was detected operation proceeds fromstep 1640 to step 1642, where the base station updates the desiredactivity level information 1644. Operation proceeds from step 1642 tostep 1638 for additional monitoring. If a signal was not detected instep 1640, operation proceeds from step 1640 to step 1638 for additionalmonitoring.

Returning to connecting node C 1610, the operation proceeds viaconnecting node C 1610 to step 1646, where the base station monitors foran override condition to occur. Step 1646 includes sub-step 1648 andsub-step 1650. In sub-step 1648, the base station monitors for receiptof a control signal indicating preemption of the first frequency band,e.g., by a government organization. In sub-step 1650, the base stationmonitors for receipt of a control signal indicating of preemption of thefirst frequency band, e.g., by a high priority user. Operation proceedsfrom step 1646 to step 1652.

In step 1652, the base station determines if a condition used tooverride the second mode of operation has occurred. If a condition hasoccurred, then operation proceeds from step 1652 to step 1654, where thebase station updates the mode override information 1656; otherwiseoperation proceeds from step 1652 to step 1646 for additionalmonitoring. Operation proceeds from step 1654 to step 1646 foradditional monitoring.

Returning to connecting node D 1612, operation proceeds via connectingnode D 1612 to step 1658, where the base station monitors for a modechange signal from a wireless terminal indicating that the wirelessterminal has the authority to alter the current mode of base stationoperation. In some embodiments, the information indicating that thewireless terminal has the authority to alter the current mode of basestation operation is one of a wireless terminal identifier, prioritylevel indicated and a wireless terminal user identifier. Operationproceeds from step 1658 to step 1660, in which the base stationdetermines whether such a mode change signal has occurred. If anauthorized mode change signal has been detected, operation proceeds fromstep 1660 to step 1662, where the base station updates the authorizedmode change information 1664; otherwise operation proceeds from step1660 to step 1658 for additional monitoring. Operation proceeds fromstep 1662 back to step 1658 for additional monitoring.

Returning to step 1618, in step 1618, the base station makes a modechange determination as a function of the activity level information1636, authorized mode change information 1664, and/or mode overrideinformation 1656. If the determination in step 1618, is that the modeshould change, then operation proceeds to step 1620, where the basestation switches from a second mode of operation to a first mode ofoperation in which the base station ceases to operate as an access node;otherwise operation proceeds from step 1618 to the input of steps 1614and 1616 and operation continues in the second mode.

From step 1620, operation proceeds to step 1622, where the base stationtransmits a first broadcast signal during a first period of time, thefirst broadcast signal conveying information indicating that the firstfrequency band is to be used as a peer to peer frequency band. Operationproceeds from step 1622 to step 1624, where the base station determineswhether the mode should be changed. The base station uses the desiredactivity level information 1642 and/or authorized mode changeinformation 1664 in deciding whether to implement a mode change. If thedecision of step 1624 is that the mode should be changed, then operationproceeds to step 1626, where the base station switches from the firstmode of operation to the second mode of operation in which the basestation operates as an access node; otherwise operation proceeds fromstep 1624 to the input of step 1622, and the base station continues tooperate in the first mode, e.g., a mode supporting use of the firstfrequency band as a peer to peer band. Operation proceeds from step 1626to the inputs of steps 1614 and step 1616, where the base stationoperates in the second mode as an access node.

FIG. 21 is a drawing of an exemplary base station 2700 in accordancewith various embodiments. Exemplary base station 2700 includes thecapability to control reallocation of frequency spectrum betweeninfrastructure use, e.g., with the communications being directed throughthe base station 2700 functioning as an access node, and peer to peerspectrum use in which direct communications links between peer wirelessterminals are used.

Exemplary base station 2700 includes a receiver module 2702, atransmission module 2704, a processor 2706, an I/O interface 2708, andmemory 2710 coupled together via a bus 2712 over which the variouselements may interchange data and information. Memory 2710 includesroutines 2714 and data/information 2716. The processor 2706, e.g., aCPU, executes the routines 2714 and uses the data/information 2716 inmemory 2710 to control the operation of the base station and implementmethods, e.g., the method of FIG. 20.

Receiver module 2702, e.g., an OFDM receiver, is coupled to receiveantenna 2701 via which the base station 2700 receives signals fromwireless terminal, e.g., when the base station is functioning as anaccess node. Transmission module 2704, e.g., an OFDM transmitter, iscoupled to transmit antenna 2703, via which the base station 2700transmits signals to wireless terminals. The transmitted signals includebroadcast signals such as beacon signals used to identify whether afrequency spectrum is to be used in an access mode of operation or in apeer to peer communications session mode of operation. When the basestation 2700 is using spectrum in an access mode of operation, thetransmitter 2704 also transmits downlink signals, e.g., pilot channelsignals, control channel signals and user data signals, e.g., trafficchannel signals to wireless terminals using the base station 2700 as apoint of network attachment.

Transmission module 2704 transmits a 1st broadcast signal during a 1stperiod of time, the first broadcast signal conveying informationindicating that a first frequency band is to be used as a peer to peerfrequency band, and transmits a second broadcast signal during a secondperiod of time, the second broadcast signal conveying informationindicating that the first frequency band is to be used as a non-peer tofrequency band during the second period of time. In some embodiments,the 1st and 2nd broadcast signals are beacon signals, e.g., OFDM beaconsignals. 1st broadcast signal is generated by base station 2700 basedupon 1st broadcast signal information 2730, e.g., informationidentifying beacon symbols in beacon signal bursts and timing beaconburst timing information representing the 1st broadcast signal, conveyspeer to peer frequency band information. 2nd broadcast signal isgenerated by base station 2700 based upon 2nd broadcast signalinformation 2732, e.g., information identifying beacon symbols in beaconsignal bursts and timing beacon burst timing information representingthe 2nd broadcast signal, and conveys non-peer to peer frequency bandinformation 2744. Thus a wireless terminal can monitor for the presenceof 1st and 2nd broadcast signals from base station 2700 and dependingupon which one is detected, determine how the first frequency band iscurrently being used.

I/O interface 2708 couples the base station 2700 to other network nodes,e.g., other base station, AAA node, home agent nodes, etc. and/or theInternet. I/O interface 2708, by coupling base station 2700 as its pointof network attachment to participate in a communications session withanother wireless terminal using a different base station as its point ofnetwork attachment.

Routines 2714 include a transmitter control module 2718, a routingmodule 2720, a mode control module 2722, a monitoring module 2724, asecurity module 2726, and an activity level monitoring module 2728. Themode control module 2722 includes an override module 2723.Data/information 2716 includes 1st broadcast signal information 2730,2nd broadcast signal information 2732, transmission timing information2734, mode of operation information 2736, detected access request signalinformation 2738, security information 2740, peer to peer frequency bandinformation 2742, non-peer to peer frequency band information 2744,network topology information 2746, current network routing information2748, determined current level of communications activity information2750 and activity level based switching criteria 2756. The determinedcurrent level of communications activity information 2750 includes adetermined bandwidth utilization level 2752 and a determined number ofactive wireless terminal users 2754. Activity level based switchingcriteria 2756 includes a bandwidth utilization switching threshold 2758and a number of active terminals switching threshold 2760.

Transmitter control module 2718 controls the transmission module 2704 totransmit said first and second broadcast signals during said first andsecond periods of time, respectively, said first and second periods oftime being non-overlapping. Routing module 2720, which is used duringthe second period of time, routes user data received over an airlinkfrom a first communications device to a second communications device viaa communications network coupled to said base station. Routing module2720 uses network topology information 2746 and current network routinginformation 2748, e.g., information identifying congestion locations,failed nodes, alternative routing costs, delay considerationinformation, etc., to determined user data routing.

Mode control module switches between first and second modes ofoperation. The current mode of operation into which the base station hasbeen switched is indicated by mode of operation information 2736. Thefirst mode of operation corresponds to a mode during the first periodsof time in which the first frequency band is being utilized as a peer topeer frequency band, while the second mode of operation is a mode ofoperation in which the first frequency band is being utilized for nonpeer to peer communications with the base station 2700 serving as anaccess node. When the mode control module 2722 switches from the secondmode of operation to the first mode of operation the mode control module2722 stops the base station 2700 from acting as an access node, e.g.,with regard to the first frequency band in the region into which the 1stbroadcast signal transmission is directed.

Monitoring module 2724 monitors for and detects signals from wirelessterminals that are seeking to use the base station 2700 as an accessnode. For example, the base station 2700 may be currently in the firstmode of operation in which the first band is being used for peer to peercommunications; however, a wireless terminal may desire that the basestation reallocate the spectrum to access node operation, and send anaccess request signal to the base station which is detected andrecovered by monitoring module 2724. The recovered information is, e.g.,detected access request signal information. In some embodiments, thedetected access request signal information includes informationindicating that the wireless terminal making the request has theauthority to command the requested change. For example, the informationindicating that the wireless terminal has the authority to alter thecurrent mode of base station operation is, in some embodimentscommunicated by one of a wireless terminal identifier, a priority levelindicated, and a wireless terminal user identifier. Security information2740 includes information utilized in making authorization evaluations,e.g., lists of authorized users, wireless terminal, and/or prioritylevel interpretation information. The base station 2700 considers therequest in making a decision as to whether or not to switch modes. Forexample, the base station switches from the first mode of operation tothe second mode of operation in response to a signal received from awireless terminal indicating that the wireless terminal is seeking touse the base station as an access node.

Security module 2726, using security information 2740, determines that asignal requesting a mode change is from a wireless terminal or userhaving the authority to command the requested mode change.

Activity level monitoring module 2728 determines the level ofcommunications activity 2750 while the base station is in the secondmode of operation functioning as an access node. The mode control module2722 is responsive to a low activity level, which it uses to initiate aswitch from the second mode of operation to the first mode of operation.In some embodiments, at some times, a low level of activity is indicatedby determined bandwidth utilization level 2752 being below apredetermined threshold, the bandwidth utilization switching threshold2758. In some embodiments, at some times a low level of activity isindicated by determined number of active wireless terminals 2754 beingbelow a predetermined threshold, the number of active terminalsswitching threshold 2760. In various embodiments, the determined numberof active wireless terminals 2754 indicates the number of wirelessterminals currently using the base station as an access point. In someembodiments, the number of active terminals switching threshold is setto 1.

Override module 2723 detects when a current mode override conditionoccurs. The current mode override condition is, e.g., the receipt of acontrol signal indicating preemption of the first frequency band. Thepreemption can be, and sometimes is, by a government organization.Alternatively, the preemption can be, and sometimes is, by a highpriority user. The control signal can be communicated over an airlinkand received via receive module 2702 or communicated over the backhaulnetwork and received via I/O interface 2708.

FIG. 22 is a drawing of a flowchart 1700 of an exemplary method ofoperating a wireless device, e.g., a mobile node, in accordance withvarious embodiments. Operation starts in step 1702, where the wirelessdevice is powered on and initialized and proceeds to step 1704, wherethe wireless device establishes a communications link with a basestation. Then, in step 1706, the wireless device monitors for broadcastsignals from the base station while maintaining the link. Operationproceeds from step 1706 to step 1708.

In step 1708, the wireless device checks whether a predetermined changein at least one of said broadcast signals indicative of a change incommunications mode of operation from a cellular mode to a peer to peermode has been detected. In some embodiments, the change in at least oneof said broadcast signals is a change in a beacon signal, e.g., a changein an OFDM beacon signal being transmitted by the base station. In somesuch embodiments, the change includes a change in informationcommunicated by the beacon signal. In various embodiments, theinformation communicated by the beacon signal indicates a peer to peermode of frequency spectrum use after said change. If in step 1708 thewireless device detected a change in a broadcast signal indicative of achange in communications mode of operation from a cellular mode to apeer to peer mode, then operation proceeds from step 1708 to step 1710;otherwise operation proceeds from step 1708 to step 1706 for additionalmonitoring.

In step 1710, the wireless device, in response to detecting the change,ceases to maintain the link. Step 1710 includes sub-step 1710 in whichthe wireless device terminates control signaling used to maintain saidlink. Operation proceeds from step 1710 to step 1714, in which thewireless device starts to maintain transmission silence. Then, in step1716, the wireless device ceases communication with the base station inthe frequency spectrum previously used by the communications link.Operation proceeds from step 1716 to step 1720. In step 1720, thewireless device switches from a cellular mode of operation to a peer topeer mode of operation. Operation proceeds from step 1720 to step 1722.

In step 1722, the wireless device checks for a peer to peer sessioninitiation event. For example, a session initiation event is, e.g., asignal from a peer requesting session establishment, or a decision bythe wireless device to attempt to establish a peer session with anotherwireless terminal detected or known to be in the region. In response toa session initiation event, operation proceeds form step 1722 to step1726, where the wireless device establishes a peer to peercommunications session with another wireless terminal. If a peer to peersession initiation event was not detected, the operation proceeds fromstep 1722 to step 1724, where the wireless device continues to maintaintransmission silence. In some other embodiments, while in the peer topeer mode, the wireless device transmits some broadcast signals, e.g.,some user beacon signals, irrespective of whether or not the wirelessterminal is in a communications session.

Operation proceeds form step 1724 or step 1726 to step 1728, where thewireless device continues to monitor for signals from the base station,e.g., broadcast signals such as beacon signals conveying spectrum usageinformation. Operation proceeds from step 1728 to step 1730. In step1730, the wireless device determines whether a broadcast signalindicating a cellular mode of operation was detected. If such a signalwas detected, operation proceeds from step 1730 to step 1732; otherwise,operation proceeds from step 1730 to step 1728 for additionalmonitoring.

In step 1732, the wireless device terminates the peer to peercommunications session with said another terminal, if such a session wasestablished. Then, in step 1734, the wireless device re-establishes alink with the base station, e.g., with the wireless device havingremained in the coverage area corresponding to the base station betweenthe time the link ceased to be maintained and the time the link wasre-established.

FIG. 23 is a drawing of an exemplary wireless terminal 2800, e.g.,mobile node in accordance with various embodiments. Exemplary wirelessterminal 2800 can, and sometimes does, switch between a cellularoperation mode and a peer to peer operational mode in response toreceived broadcast signals, e.g., beacon signals. Wireless terminal 2800includes a receiver module 2802, a transmitter module 2804, a processor2806, user I/O devices 2808, and memory 2810 coupled together via a bus2412 over which the various elements may interchange data andinformation. Memory 2810 includes routines 2814 and data/information2816. The processor 2806, e.g., a CPU, executes the routines 2814 anduses the data/information 2816 in memory 2810 to control the operationof the wireless terminal 2800 and implement methods, e.g., a method inaccordance with FIG. 22.

Routines 2814 include a communications routine 2818 and wirelessterminal control routines 2820. The communications routine 2818implements the various communications protocols used by the wirelessterminal 2800. Wireless terminal control routines 2820 include a linkestablishment module 2822, a broadcast signal monitoring module 2824, amode determination module 2826, a mode control module 2828, a controlsignaling module 2830, a link re-establishment module 2832, and a peerto peer communications establishment module 2834. Mode control module2828 includes switching module 2829.

Data/information 2816 includes detected broadcast signal information2836, detected change in broadcast signal information 2840, determinedmode of operation communicated by broadcast signaling 2842, spectrumusage information 2848, wireless terminal current mode of operationinformation 2844, and generated control signals 2846. Data/information2816 also includes broadcast signals' identification information 2850and broadcast signals' information recovery information 2852. Thebroadcast signals' identification information 2850 includes beaconsymbol energy level detection information 2854, and beacon symbolpattern information 2856. Broadcast signals' information recoveryinformation 2852 includes beacon signal to mode mapping information 2858and beacon signal to spectrum usage mapping information 2860.

Receiver module 2802, e.g., an OFDM receiver, is coupled to receiveantenna 2803 via which the wireless terminal receives signals. Receivermodule 2802 receives broadcast signals from base stations. The broadcastsignals include, e.g., beacon signaling used to communicate a currentmode of spectrum usage. When the base station is functioning as anaccess node, the wireless terminal receiver 2802 can, and sometimesdoes, receive control signals and user data signals from the basestation in the spectrum. When the spectrum is being utilized for peer topeer communications, the wireless terminal receiver 2802 can, andsometimes does, receive signals directly from a peer wireless terminal,e.g., user beacon signals, peer to peer session establishment signals,and user data signals as part of a peer to peer communication session.

Transmitter module 2804, e.g., an OFDM transmitter, is coupled totransmit antenna 2805 via which the wireless terminal 2800 transmitssignals. In some embodiments, the same antenna is used by thetransmitter and receiver. Transmitted signals include, e.g., access nodebased session establishment signals, peer to peer node sessionestablishment signals, control signal to an access node as part ofmaintaining a link with the access node, user data signals to an accessnode, and user data signals to a peer node as part of a peer to peercommunication session.

User I/O devices 2808 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2808 are used foroperations including inputting user data, and controlling at least somefunctions and operations of the wireless terminal, e.g., initiating acommunications session.

Link establishment module 2822 establishes a communications link with abase station. Broadcast signal monitoring module 2824 monitors to detectbroadcast signals from base stations. Mode determination module 2826determines a communications mode of operation from at least onebroadcast signal from a base station detected by the monitoring ofmodule 2824. In various embodiments, the broadcast signal from the basestation used by the mode determination module 2826 for its determinationis a beacon signal. In some embodiments, the mode determination is basedon a change in a beacon signal, e.g., as indicated in detected change inbroadcast signal information 2840. In some such embodiments, the changeindicates a change in information communicated by the beacon signal. Forexample, the information communicated by the beacon signal indicates apeer to peer frequency spectrum use after the change, while the beaconsignal information before the change indicates a cellular mode usage ofthe spectrum. As another example, the information communicated by thebeacon signal indicates a cellular mode spectrum use after the change,while the beacon signal information before the change indicates a peerto peer mode usage of the spectrum.

Mode control module 2828 controls the wireless terminal 2800 to operatein the mode determined by the mode determination module 2826. The modecontrol module 2828 can, and sometimes does, drop an established linkwith a base station when the mode determination module 2826 indicates achange in a communication mode of operation from a cellular mode to apeer to peer mode of operation. Switching module 2829 switches thewireless terminal 2800 from a cellular mode of operation to a peer topeer mode of operation in response to detecting a predetermined changein at least one of the broadcast signals. Wireless terminal current modeof operation 2844 indicates the current mode of wireless terminaloperation, e.g., cellular mode or peer to peer mode, into which thewireless terminal has been switched.

Control signaling module 2830 generates control signals 2846 to maintainan established link with a base station. Generated control signals 2846include, e.g., power control signals, timing control signals, controlchannel report signals such as SNR reports, etc. When the mode controlmodule 2828 drops an established link with a base station, the modecontrol module 2828 controls the control signaling module 2830 to stopgenerating control signals used to maintain the link.

Link re-establishment module 2832 re-establishes a link with a basestation in response to detecting a broadcast signal indicating acellular mode of operation. Peer to peer communications establishmentmodule 2834 is used to establish a peer to peer communications sessionwith another wireless terminal, e.g., during at least a portion of thetime between which said link is ceased to be maintained with the basestation and the link is re-established with the base station.

Detected broadcast signal information 2836, e.g., detected beacon signalinformation is an output of broadcast signal monitoring module 2824.Broadcast signal monitoring module 2824 uses the data/information 2816including the broadcast signals' identification information 2850 todetect beacon signals. Beacon symbol energy level detection information2854 includes energy level criteria used for identifying beacon symbolsfrom among a plurality of received signals. For example, a beacon signalincludes a beacon signal burst including at least a beacon symbol andthe beacon symbol is transmitted at a relatively high energy level withrespect to other signals transmitted by the base station, facilitatingeasy detection by a wireless terminal. Beacon symbol pattern information2856 includes information identifying sets of beacon symbols within aset of beacon symbol transmission units. For example, a particularpattern of beacon symbols may, and sometimes does represent a particularbeacon signal.

Mode determination module 2826 uses the data/information 2816 includingthe broadcast signals' information recovery information 2852 todetermine a mode of operation being communicated by the broadcast signal2842, e.g., one of a cellular mode and a peer to peer mode, and spectrumusage information 2848, e.g. one of a cellular mode spectrum allocationand a peer to peer mode spectrum allocation. In some embodiments thecellular mode spectrum usage information further identifies one of atime division duplex use of spectrum and a frequency division duplex useof spectrum. For example, the base station when functioning as an accessnode may operate in a TDD manner in which the spectrum is alternatelyused for downlink and uplink, or the base station may operate using twodistinct bands for uplink and downlink which allow simultaneous uplinkand downlink signaling.

FIG. 24 is a drawing of a flowchart 1800 of an exemplary method ofoperating a mobile communications device in a system including a basestation in accordance with various embodiments. Operation starts in step1802, where the mobile communications device is powered on andinitialized and proceeds to step 1804. In step 1804, the mobilecommunications device determines a base station mode of operation, thebase station mode of operation being one of an access mode of operationin which the base station operates as a network access node and a peerto peer mode of operation in which devices within a base stationcoverage area are allowed to communicate directly with one another.Operation proceeds from step 1804 to step 1806.

In step 1806, the mobile communications device, sends a signal to a basestation to signal a wireless terminal desired change in the mode of basestation operation. Then, in step 1808, the mobile communications devicemonitors for a broadcast signal from the base station indicating achange in base station mode of operation to the indicated mode desiredby the mobile communications device. Operation proceeds from step 1808to step 1810. In step 1810, the mobile communications device checks ifthe monitored for signal has been detected. If the monitored for signalwas detected, then operation proceeds from step 1810 to step 1812;otherwise, operation proceeds from step 1810 to step 1808 for additionalmonitoring. In some embodiments, a timeout is associated with theduration of the monitoring, and if the mobile communications device doesnot receive the monitoring, and if the mobile communications device doesnot receive the monitored for signal within the allocated time, themobile communications device needs to resend the desired change signal.

In step 1812, the mobile communications device changes the mode of themobile communications device operation to the mode to which the basestation has changed. Operation proceeds from step 1812 to step 1814. Instep 1814, the mobile communications device signals the base station toswitch from the indicated mode of operation to the base station'sprevious mode of operation.

In some embodiments, the signal of step 1804 indicates a desire for achange from a network access mode of operation to a peer to peer mode ofoperation. In some embodiments, the signal of step 1804 includesinformation indicating a level of authority said mobile communicationsdevice has to control the base station operation. In some suchembodiments, the information indicating the level of authority is one ofa device identifier, user identifier, and priority level indicator.

In various embodiments, the mobile communications device is a deviceused by a government agent with authority to override use of thespectrum used by the base station.

In some embodiments, the mobile communications device is a cellularnetwork device, and the desired change of step 1806 is a change from apeer to peer mode to a network mode of operation. In some suchembodiments, the cellular network device does not support peer to peeroperation.

In various embodiments, the mobile communications device is a peer topeer device and the desired change is a change from a network accessmode to a peer to peer mode of operation. In some such embodiments, thepeer to peer device does not support a cellular network mode ofoperation. In some embodiments, the peer to peer device which does notsupport a cellular network mode of operation is a device used by agovernment agent with authority to override the use of the spectrum bythe base station.

FIG. 25 is a drawing of an exemplary wireless terminal 2900, e.g.,mobile node, in accordance with various embodiments. Exemplary wirelessterminal 2900 includes the capability to influence a base station's modeof operation, e.g., requesting and/or commanding switching between acellular mode and a peer to peer mode.

Exemplary wireless terminal 2900 includes a receiver module 2902, atransmitter module 2904, a processor 2906, user I/O devices 2908, andmemory 2910 coupled together via a bus 2912 over which the variouselements may exchange data and information. Memory 2910 includesroutines 2914 and data/information 2916. The processor 2906, e.g., aCPU, executes the routines 2914 and uses the data/information 2916 inmemory 2910 to control the operation of the wireless terminal andimplement methods, e.g., a method in accordance with FIG. 24.

Routines 2914 include communications routines 2918 and wireless terminalcontrol routines 2920. The wireless terminal control routines 2920include a base station mode of operation determination module 2922, asignal generation module 2924, a broadcast signal detection module 2928and a communications mode control module 2930. The signal generationmodule 2924 includes a base station mode restoration module 2926.

Data/information 2916 includes a determined base station mode ofoperation 2932, a generated change signal 2934, and stored informationindicating the level of authority the wireless terminal has to controlthe base station operations 2936. Information 2936 includes a wirelessterminal device identifier 2938, a wireless terminal user identifier2940, and a priority level indicator 2942. Data/information 2916 alsoincludes detected broadcast signal information 2944 and current mode ofwireless terminal operation information 2946.

The receiver module 2902, e.g., an OFDM receiver, is coupled to receiveantenna 2903, via which the wireless terminal 2900 receives signals.Received signals include received broadcast signals, e.g., beaconsignals, from a base station from which a base station mode of operationcan be determined.

Transmitter module 2904, e.g., an OFDM transmitter, is coupled totransmit antenna 2905, via which the wireless terminal 2900 transmitssignals. Transmitted signals include generated change signal 2934conveying a wireless terminal 2900 desire for a base station to changeits mode of operation. Transmitter module 2904 sends the generatedchange signal 2934 to the base station to communicate the wirelessterminal's desired change in the base station's mode of operation. Thegenerated change signal 2934 can be, and sometimes is, a command to thebase station to change its mode of operation.

User I/O devices 2908 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2908 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a communications session. In someembodiments, the user I/O devices 2908 include a special purpose key,switch or button, for use to command a mode switch of the base station.For example, the wireless communications device 2900 is used by agovernment agent with authority to override use of the spectrum by thebase station and includes a special purpose button on the wirelessterminal, which when depressed, initiates the generation andtransmission of a mode change control signal directed to the basestation.

Communications routine 2918 implements the various communicationsprotocols used by the wireless terminal 2900. Base station mode ofoperation determination module 2922 determines a base station's mode ofoperation, the base station mode of operation being one of an accessnode mode of operation in which the base station operates as a networkaccess node and a peer to peer mode of operation in which devices withina base station coverage area are allowed to communicate directly withone another. Determined base station mode of operation 2932 is an outputof determination module 2922.

Signal generation module 2924 generates a signal change signal 2934indicating a wireless terminal desired change in the base station's modeof operation. At times, the generated change signal 2934 indicates adesire for a change from a network access mode of operation to a peer topeer mode of operation. At times, the generated change signal 2934indicates a desire for a change from a peer to peer mode of operation tonetwork access mode of operation.

In some embodiments, the change signal conveys a level of authorityassociated with the change signal. The level of authority, in someembodiments, is based on one or more of wireless terminal identifier,user identifier, and a priority level indicator. In some embodiments,wireless terminal 2900 has a fixed level of authority associated withthe device. In some embodiments, wireless terminal 2900 has a variablelevel of authority, e.g., which changes a function of useridentification information and/or priority level access codeinformation. In some such embodiments, the user I/O devices 2908 includea biometric input device for receiving biometric informationcorresponding to the user, the input biometric information being used toobtain/authenticate authorization information.

Base station mode restoration module 2926 generates a restoration signal2935 to be communicated to a base station, the restoration signal tosignal the base station to switch from the indicated mode of operationcommunicated by the previous change signal to the base station, theindicated mode being the mode in which the base station is currentlyoperating, to the previous mode of base station operation.

Broadcast signal detection module 2928 detects a broadcast signal whichindicates that the base station has changed the base station mode ofoperation to an indicated mode of operation desired by the wirelessterminal. Detected broadcast signal information 2944 is an output ofdetection module 2928. In various embodiments, the detected broadcastsignals are beacon signals, e.g., OFDM beacon signal. Communicationsmode control module 2930 changes the operational mode of the mobilecommunications device, as indicated by current mode of wireless terminaloperation, to match the mode of base station operation to which the basestation has transitioned as indicated by a detected broadcast signal. Invarious embodiments, the wireless terminal 2900 supports communicationssessions in both cellular and peer to peer modes of operation. In somesuch embodiments, the wireless terminal enters a standby state while thespectrum is allocated for the mode in which the wireless terminal cannot participate in a communication session, e.g., conserving power.

In some embodiments, the wireless terminal 2900 is a device used by agovernment agent with the authority to override use of the spectrum usedby a base station. In some embodiments, the wireless terminal 2900 is acellular network device, and the wireless terminal indicates a desiredchange from a peer to peer to a network access mode of operation. Insome such embodiment, the cellular network device does not support peerto peer communications. In some embodiments, the wireless terminal 2900is a peer to peer device, and the wireless terminal indicates a desiredchange from a network access mode of operation. In some suchembodiments, the cellular network device does not support a cellularnetwork mode of operation. In some embodiments, the wireless terminal isa mobile communications device used by a government agent with authorityto override use of the spectrum by the base station.

In one embodiment, which is a variation based on wireless terminal 2900,the wireless terminal is a mobile communications device used by agovernment agent with the authority to override the use of spectrum bythe base station, and the device communicates mode change commandsignals, but does not support either access node based or peer to peerbased communications sessions.

FIG. 26 is a drawing of a flowchart 1900 of an exemplary method ofoperating a wireless device, e.g., a mobile node, in accordance withvarious embodiments. Operation starts in step 1902, where the wirelessdevice is powered on and initialized. Operation proceeds from start step1902 to step 1904, where the wireless device receives a first broadcastsignal from a base station. Then, in step 1906, the wireless devicedetermines from the received first broadcast signal that a frequencyband corresponding to the base station is being used for peer to peercommunications. Operation proceeds from step 1906 to step 1908.

In step 1908, the wireless device receives a second broadcast signalfrom the base station, and then in step 1910, the wireless devicedetermines from the received second broadcast signal that the secondfrequency band has been changed to be used as a cellular network band.In response to determining that the frequency band is to be used as acellular frequency band, operation proceeds from step 1910 to one ofalternate steps 1912, 1914, and 1916. In alternative step 1912, thewireless device reduces transmission power. In some embodiments,reducing transmission power includes a reduction in transmission powerby at least 10 dBs. In some embodiments, reducing transmission powerincludes ceasing to transmit. In alternative step 1914, the wirelessdevice terminates an ongoing peer to peer communications session. Inalternative step 1916, the wireless device puts an ongoing peer to peercommunications session into a hold state. Operation proceeds from any ofsteps 1912, 1914, 1916 to step 1918. If the wireless terminal does nothave an ongoing peer to peer communications session, when making thedetermination of step 1910, operation proceeds from step 1910 to step1918 without traversing alternative steps 1912, 1914, or 1916.

In step 1918, the wireless device receives a third broadcast signal fromthe base station, and then in step 1920, the wireless device determinesfrom the third broadcast signal that said frequency band has beenchanged to be used for peer to peer communications.

Operation proceeds from step 1920 to step 1922, where the wirelessdevice switches a peer to peer communications session, which was in holdstate, if one happens to exist in hold state, to an active state inresponse to said third broadcast signal.

In some embodiments at least some of the received first, second andthird broadcast signals include beacon signal bursts. In someembodiments, each of the first, second, and third signals are OFDMbeacon signals.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments. Exemplarywireless terminal 3000 supports peer to peer communications sessions. Insome embodiments, exemplary wireless terminal 3000 supports peer to peercommunications but does not support a cellular mode of operation.Exemplary wireless terminal 3000 includes a receiver module 3002, atransmission module 3004, a coupling module 3003, a processor 3006, userI/O devices 3008, a power supply module 3010 and memory 3012 coupledtogether via a bus 3014 over which the various elements may interchangedata and information. Memory 3012 includes routines 3016 anddata/information 3018. The processor 3006, e.g., a CPU, executes theroutines and uses data/information 3018 in memory 3012 to control theoperation of the wireless terminal 3000 and implement methods, e.g., amethod in accordance with FIG. 26.

Coupling module 3003, e.g., a duplex module, couples the receiver module3002 to antenna 3005 and the transmission module 3004 to antenna 3005,e.g., coordinating tome division duplex operations of wireless terminal3000. Power supply module 3012, which includes a battery 3011, is usedto power up the various components of the wireless terminal 3000. Poweris distributed from the power supply module 3010 to the variouscomponents (3002, 3003, 3004, 3006, 3008, 3012), via a power bus 3009.User I/O devices 3008 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 3008 are used foroperation including inputting user data, accessing output user data, andcontrolling at least some functions and operations of the wirelessterminal, e.g., initiating a peer to peer communications session.

Routines 3016 include a mode determination module 3020, a mode controlmodule 3022, a peer to peer communications session termination module3024, a session hold module 3026, and a peer to peer communicationssession reestablishment module 3028. Data/information 3018 includesreceived broadcast signals 3030, a determined mode of communicationsoperation 3032, wireless terminal controlled mode information 3034, acurrent level of transmission power information 3035, power reductioninformation 3036, 1st maximum transmission power level information 3038,2nd maximum transmission power level information 3040, and peer to peercommunications session information 3042. The peer to peer communicationssession information 3042 includes status information 3044, peer nodeinformation 3046, user data information 3048, and state information3050.

Receiver module 3002, e.g., an OFDM receiver, receives signals includingbroadcast signals. Receiver module 3002 also receives, at times, userdata signals from a peer wireless terminal in a peer to peercommunications session with wireless terminal 3000. Received broadcastsignals 3030, e.g., beacon signals, are used to determine a mode ofcommunication band operation.

Transmitter module 3004, e.g., an OFDM transmitter, transmits user dataas part of a peer to peer communications session. In some embodiments,transmission module 3004 also transmits user beacon signals, e.g. OFDMuser beacon signals.

Mode determination module 3020 determines based on received broadcastsignals 3030 a mode of communications band operation, determined mode ofcommunications band operation 3032. The determined mode ofcommunications band operation indicating a mode of operation in whichthe frequency band is to be used at a point in time, the determined modeof communication band operation being one of a plurality of frequencyband modes including at least a cellular communications mode and a firstpeer to peer communications mode.

Mode control module 3022 controls wireless terminal 3000 deviceoperation as a function of at least one of a mode determination and achange in a determined mode of communications band operation, said modecontrol module 3022 controlling the transmitter to reduce power inresponse to determining that the frequency band is to be used as acellular frequency band. In some embodiments, the controlling thetransmitter to reduce power includes reducing transmission power by atleast 10 dBs. In some embodiments reducing transmission power includesceasing to transmit.

Thus, in some embodiments, when wireless terminal 3000 is in a peer topeer communications session and the spectrum is reallocated to supportaccess node based operations, the wireless terminal is permitted tocontinue the peer to peer communications session at a reduced powerlevel. While, in other embodiments, when wireless terminal 3000 is in apeer to peer communications session and the spectrum is reallocated foraccess node based operation, the wireless terminal terminates orsuspends the peer to peer communications session until the spectrum isreallocated for peer to peer usage. In some embodiments, wirelessterminal 3000 decides whether to continue with, terminate, or place onhold a peer to peer session interrupted by a spectrum reallocation, inresponse to other factors, e.g., device identification information, useridentity information, priority information, latency requirements, etc.

Peer to peer communications session termination module 3024 terminatesat least some peer to peer communications sessions in response to adetermination that a frequency band is being used as a cellularfrequency band. Session hold module 3026 puts an ongoing peer to peercommunications session into a hold state in response to a determinationthat the frequency band is being used as a cellular frequency band. Peerto peer communications session reestablishment module 3028 transitions apeer to peer communications session from a hold state to an active statein response to a determination that the frequency band is to be used forpeer to peer communications.

Current level of transmission power information 3035 is a monitoredlevel used by mode control module 3022, when determining a transmissionpower level reduction in accordance with power reduction information3036, e.g., a gain factor of at least 10 dBs, 1st maximum transmissionpower level information 3038 and 2nd maximum level transmission powerinformation 3040. The power level reduction is in response to sdetection that spectrum usage is changing from peer to peer to cellularbased, and the wireless terminal 3000 continuing with the peer to peercommunications session at a reduced power level. In some embodiments,the mode control module 3022 supports 1st and 2nd modes of peer to peeroperation from the perspective of the wireless terminal, the second peerto peer mode of operation being a reduced power level mode of operationin which the wireless communications device 3000 uses a lower maximumtransmission power level for the transmission of user data than is usedin the 1st mode of peer to peer operation. In some embodiments, the 1stmode of wireless terminal peer to peer operation applies when thespectrum is allocated for peer to peer usage, and the second mode ofwireless terminal peer to peer operation applies when the spectrum isallocated primarily for cellular access node base operations.

Status information 3044 indicates whether the peer to peercommunications session is in an active state or a hold state. Statusinformation 3044 also indicates whether the peer to peer communicationssession is in a first mode of wireless terminal peer to peer operation,e.g., normal power mode, or a second mode of wireless terminal peer topeer operation, reduced power mode. Peer node information 3046 includespeer node identification information, addressing information, andpriority level information. User data information 3048, e.g., voice,image, text, file information, includes user data to be transmitted andreceived as part of the peer to peer communications session. Stateinformation used to reestablish a session placed into a hold state.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawingof a flowchart 2000 of an exemplary communications method in accordancewith various embodiments. Operation of the exemplary communicationsmethod starts in step 2002 and proceeds to step 2004, step 2024 viaconnecting node A 2006, and step 2030 via connecting node B 2008.

In step 2004, a first wireless terminal capable of supporting peer topeer operations and cellular network operations is operated. Step 2004includes sub-step 2010, 2011, 2012, 2014, 2016, 2018, and 2020. Insub-step 2010, the first wireless terminal monitors for paging signalsfrom a base station during a first set of time intervals which arepaging time intervals. In various embodiments, during the first set oftime intervals the first wireless terminal does not transmit peer topeer signals. In some embodiments, during the first set of timeintervals the first wireless terminal also does not receive peer to peersignals.

In sub-step 2012, the first wireless terminal, during a second set oftime intervals, which do not overlap said first set of time intervals,is operated to participate in a peer to peer communications session. Insome embodiments, the first and second time intervals are interleaved.Sub-step 2012 includes sub-step 2022, in which the first wirelessterminal, during at least a portion of said second set of time intervalsis operated to transmit a first wireless terminal identifier used forpeer to peer communications. In some such embodiments, the firstwireless terminal identifier is communicated via a user beacon signal,e.g., an OFDM user beacon signal including a beacon signal burstincluding at least one beacon symbol.

In some embodiments, the same frequency band is used for paging and forpeer to peer communications, and the first wireless terminal need notperform sub-step 2011. In some embodiments, different frequency bandsare used for paging and for peer to peer communications. In some suchembodiments, sub-step 2011 is performed in which the first wirelessterminal switches the frequency band of a receiver in said wirelessterminal when switching between monitoring for pages during a first timeinterval and operating in a peer to peer mode during a second timeinterval.

Returning to sub-step 2010, for a detected page signal directed to thefirst wireless terminal, operation proceeds from sub-step 2010 tosub-step 2014. In sub-step 2014, the first wireless terminal decideswhether to establish a link with the base station in response to thepage directed to the first wireless terminal or to continue with anongoing peer to peer communication session. In some embodiments, thedecision of the step 2014 is a function of at least one of: a prioritylevel associated with the ongoing peer to peer communications session, apriority level associated with the peer wireless terminal in the ongoingpeer to peer communications session, a priority level associated withthe user of the peer wireless terminal in the ongoing peer to peercommunication session, the type of data being communicated in the peerto peer communications session, latency considerations of the data beingcommunicated in the peer to peer session, an estimate of the amount ofdata remaining to be communicated in the peer to peer communicationssession, and priority information communicated in the page signal. Insome such embodiments, the decision of step 2014 is a function of atleast two of: a priority level associated with the ongoing peer to peercommunications session, a priority level associated with the peerwireless terminal in the ongoing peer to peer communications session, apriority level associated with the user of the peer wireless terminal inthe ongoing peer to peer communication session, the type of data beingcommunicated in the peer to peer communications session, latencyconsiderations of the data being communicated in the peer to peersession, an estimate of the amount of data remaining to be communicatedin the peer to peer communications session, and priority informationcommunicated in the page signal.

If the decision of sub-step 2014 is to establish a link with the basestation which transmitted the page, then operation proceeds to sub-step2016, where the first wireless terminal terminates the peer to peercommunications session and in sub-step 2018 establishes a link with thebase station. However, if the first wireless terminal decides insub-step 2014 to continue with the ongoing peer to peer communicationsession, operation proceeds from sub-step 2014 to sub-step 2020 wherethe first wireless terminal continues with the peer to peercommunications session. In some such embodiments, the first wirelessterminal, when deciding to perform sub-step 2020, the first wirelessterminal ignores the page, e.g., with no response back to the basestation. In other embodiments, the first wireless terminal, whendeciding to perform sub-step 2020, sends a page response signal to thebase station indicating the first wireless terminal has received thepage but has decided not to establish a link with the base station.

Returning to step 2024, in step 2024, a second wireless terminal,capable of supporting peer to peer mode operations and cellular networkoperations, is operated. Step 2024 includes sub-steps 2026 and 2028. Insub-step 2026, the second wireless terminal monitors for paging signalsfrom a base station during a third set of time intervals which arepaging tie intervals. In some such embodiments, the first and thirdpaging time intervals overlap. In sub-step 2028, the second wirelessterminal, during said second set of time intervals, which does notoverlap with said first or third set of time intervals participates in apeer to peer communications session.

Returning to step 2030, in step 2030, a third wireless terminal isoperated in a peer to peer communications session during which at leastsome first time periods occur, wherein the third wireless terminal doesnot perform paging operations between the start and end of its peer topeer communications session and remains silent during the first timeintervals occurring between the start and end of its peer to peercommunications session.

FIG. 29 is a drawing of an exemplary wireless terminal 3100, e.g.,mobile node, in accordance with various embodiments. Exemplary wirelessterminal 3100 monitors for, detects, and processes paging signals in awireless communications system including dual mode capability includingaccess node based cellular communications and peer to peercommunications, and exemplary wireless terminal 3100 supports operationin both modes of operation.

Exemplary wireless terminal 3100 includes a receiver module 3102, atransmitter module 3104, a processor 3106, user I/O devices 3108, andmemory 3110 coupled together via a bus 3112 over which the variouselements may exchange data and information. User I/O devices 3108include, e.g., keypad, keyboard, switches, mouse, microphone, speaker,display, etc. User I/O devices 3108 are used for operation includinginputting user data, accessing output user data, and controlling atleast some functions and operations of the wireless terminal, e.g.,initiating a peer to peer communications session or initiating an accessnode based communications session.

Transmitter module 3104, e.g., an OFDM transmitter, is coupled totransmit antenna 3105, via which the wireless terminal 3100 transmitssignals. Transmitted signals include generated identification signals3142, e.g., an OFDM user beacon signal including beacon signal burst,each beacon signal burst including at least one OFDM beacon symbol.Transmitted signals also include access node based session establishmentsignals, peer to peer session establishment signals, control and userdata uplink signals directed to a base station serving as the wirelessterminal's point of network attachment, signals directed to a peer nodeas part of a peer to peer communications session, and uplink pageresponse signals directed to the base station which transmitted the pagedirected to wireless terminal 3100.

Memory 3110 includes routines 3114 and data/information 3116. Theprocessor 3106, e.g., a CPU, executes the routines 3114 and uses thedata/information 3116 in memory 3110 to control the operation of thewireless terminal and implement methods. Routines 3114 include acommunications routine 3118 and wireless terminal control routines 3120.The communications routine 3118 implements the various communicationsprotocols used by the wireless terminal 3100. The wireless terminalcontrol routines 3120 include a time interval determination module 3122,a cellular network communications module 3124, a page signal monitoringmodule 3126, a peer to peer communications module 3128, a wirelessterminal identification signal generation module 3130, a decision module3132, and a peer to peer communications session termination module 3134.The peer to peer communications module 3128 includes a peer to peercommunications control module 3129.

Data/information 3116 includes a determined first set of time intervals3136, which are paging time intervals, a determined second set of timeintervals 3138, a detected page signal 3140, a generated wirelessterminal identification signal, e.g., a generated user beacon associatedwith wireless terminal 3100, paging band information 3144, peer to peerband information 3146 and receiver band setting information 3148.

Time interval determination module 3122 determines first and second setsof time intervals (3136, 3138), respectively), the first and second setsof time intervals being a non-overlapping sets, the first set of timeintervals being paging time intervals. Cellular network communicationsmodule 3124 supports cellular network communications operations, e.g.,operations in which the wireless terminal uses the base station as anetwork attachment point to communicate with another wireless terminalvia the cellular communications network. Page signal monitoring module3126 monitors for paging signals from a base station during the firstset of time intervals 3136. Information 3140 represents a detected pagesignal directed to wireless terminal 3100.

Peer to peer communications module 3128 supports peer to peercommunications signaling operations during the second set of timeintervals 3138 but not during the first set of time intervals 3136. Peerto peer transmission control module 3129 restrains the wireless terminalfrom transmitting peer to peer signals during the first time intervals.In some embodiments, the wireless terminal is also controlled to suspenddetection operations of peer to peer signals during the first timeintervals. In various embodiments, members of the first set of timeintervals are interleaved with members of the second set of timeintervals.

Wireless terminal identification signal generation module 3130 generatesa wireless terminal identifier 3142 used for peer to peercommunications, e.g., an OFDM beacon signal burst or sequence of bursts,each beacon signal burst including at least one beacon symbol. Decisionmodule 3132 decides between establishing a communication link with abase station in response to a page which was received or continuing withan on-going peer to peer communications session. Peer to peercommunications session termination module 3134 terminates a peer to peercommunications session in response to a received page directed to thewireless terminal 3100.

Paging band information 3144 includes information identifying thefrequency band used for paging, while peer to peer band information 3146identifies the frequency band used for peer to peer communications. Insome embodiments the same frequency band is used for paging and peer topeer communications. In some embodiments, different frequency bands areused for paging and peer to peer communications. In some suchembodiments, receiver module 3102 includes a tunable receiver responsiveto a mode control signal for switching between the different frequencybands used for paging and peer to peer communications. Receiver bandsetting information 3148 includes information indicating the currentsetting of the receiver module 3102 and control signaling used to changethe setting of the receiver module 3102.

FIG. 30 is a drawing of an exemplary communications system 2100 inaccordance with various embodiments. Exemplary communications system2100 includes a plurality of base stations (base station 1 2102, basestation 2 2104, base station 3 2106) and a plurality of non-accessbeacon signal transmitter nodes (non-access beacon signal transmitternode 1 2108, non-access beacon signal transmitter node 2 2112,non-access beacon signal transmitter node 3 2110). The base stations(2102, 2104, 2106) are coupled to network nodes (2114, 2118, 2118) vianetwork links (2120, 2128, 2126), respectively. In addition, system 2100includes network node 2116 which is coupled to (network node 2114,network node 2118, non-access beacon signal transmitter 2108, and othernetwork nodes and/or the Internet) via network links (2122, 2124, 2130,2131), respectively. Network links (2120, 2122, 2124, 2126, 2128, 2130,2131) are, e.g., fiber optic links and/or wired links.

Some of the base stations (BS 1 2102, BS 2 2104) support both peer topeer communications in the base station region and also operate asaccess nodes. Base station 3 2106 functions as an access node and doesnot support peer to peer communications in its coverage region. Eachbase station (BS 1 102, BS 2 2104, BS 3 2106) has a corresponding region(2103, 2105, 2107) which represents a cellular coverage area when in thenetwork access mode. Regions (2103, 2105) also represent base stationbeacon transmission regions when supporting peer to peer communications.

The base stations (2102, 2104, 2106) and the non-access beacon signaltransmitter nodes (2108, 2110, 2112) transmit beacon signals includingbeacon signal bursts, e.g., OFDM beacon signal bursts each beacon signalburst including at least one beacon symbol.

Exemplary system 2100 also includes a plurality of wireless terminals,e.g., mobile nodes, (MN 1 2150, MN 2 2152, MN 3 2154, MN 4 2156, MN 52158, MN 6 2160, MN 7 2162, MN 8 2164), which may move throughout thesystem. MN 1 2150 is using BS 1 2102 as an access node and is coupled toBS 1 2102 via link 2166. MN 2 2152 is using BS 1 2102 as an access nodeand is coupled to BS 1 2102 via link 2168. MN 1 2150 and MN 2 2152 areusing access node beacon signals transmitted from BS 1 2102 forsynchronization. MN 3 2154 is in a peer to peer communications sessionwith MN 4 2156 using peer to peer link 2170. MN 3 2154 and MN 4 2156 areusing peer to peer beacon signals from BS 1 2102 for synchronizationpurposes.

MN 5 2158 is using BS 3 2106 as an access node and is coupled to BS 32106 via link 2172. MN 6 2160 is using BS 3 2106 as an access node andis coupled to BS 3 2106 via link 2174. MN 5 2158 and MN 6 2160 are usingaccess node beacon signals transmitted from BS 3 2174 forsynchronization.

MN 7 2162 is in a peer to peer communications session with MN 8 2164using peer to peer link 2176. MN 7 2162 and MN 8 2164 are using peer topeer beacon signals from non-access beacon signal transmitter node 32110 for synchronization purposes.

Base station 1 2102 includes a peer to peer beacon signal generationmodule 2132, an access node beacon signal generation module 2134, atransmitter module 2136, a receiver module 2138 and a switching module2140. Peer to peer beacon signal generation module 2132 generates beaconsignals used to support peer to peer communications, while access nodebeacon signal generation module 2134 generates beacon signals used tosupport cellular network communications. Transmitter module 2136, e.g.,an OFDM transmitter, transmits generated peer to peer beacon signals andgenerated access node beacon signals. Transmitter module 2136 alsotransmits control and user data signals to wireless terminals whenfunctioning as an access node. Receiver module 2138, e.g., an OFDMreceiver, receives signals such as access request signals, controlsignals and user data from wireless terminals, e.g., mobile nodes usingthe base station as a point of network attachment. Switching module 2140supports switching between peer to peer and cellular modes of operationusing the same frequency band for peer to peer and cellular modes ofoperation at different times. Base station 1 2102 transmits differentbeacon signals during peer to peer and cellular modes of operation.

Non-access beacon signal transmitter node 2 2112 and non-access beaconsignal transmitter node 3 2110 are standalone devices. Non-access beaconsignal transmitter node 2 2112 includes a transmitter 2142, a battery2144 and a receiver 2146. Battery 2144 powers non-access beacon signaltransmitter node 2 2112. Transmitter coverage region 2113 forsynchronization purposes in supporting peer to peer communicationssessions. The beacon signal transmitter 2142 does not relay any userdata. Receiver 2146 for receiving a broadcast signal used for timingsynchronization purposes is one of a GSM receiver, a satellite receiver,and a cellular network receiver. Satellite receivers include, e.g., aGPS receiver, broadcast TV and/or radio signal satellite receiver,proprietary satellite receiver or government controlled satellitereceiver. Cellular network receivers include, e.g., CDMA, OFDM, GSM,etc., receivers. In some embodiments, a non-access beacon signaltransmitter node includes a plurality of different types of receiversfor receiving different types of broadcast signals, e.g., with differentsignals being available in some areas but not in others.

In various embodiments, at least some of the base stations, whichtransmit beacon signals are not synchronized with respect to oneanother. In various embodiments, at least some of the non-access beaconsignal transmitter nodes, which transmit beacon signals, are notsynchronized with respect to one another. For example, non-access beaconsignal transmitter node 3 2110, in some embodiments, does not include areceiver, and its transmitted beacon signals into its transmitter region2111 are free running with respect to the other non-access beacon signaltransmitters in system 2100 and the base stations in system 2100.

Non-access beacon signal transmitter module 3 2110 includes a solar cell2148, and the solar cell 2148 is a solar power source conversion devicefor powering non-access beacon signal transmitter node 3 2110 during atleast some of the time.

Non-beacon access beacon signal transmitter node 1 2108 is coupled tothe network via link 2130 thus facilitating timing synchronizationinformation to be communicated to the node 2108, allowing for its beaconsignal transmission into its transmitter region 2109 to be synchronizedwith respect to an overall system timing reference. No user data iscommunicated over link 2130.

FIG. 31 is a drawing of an exemplary wireless communications system 2200which supports both peer to peer communications and cellularcommunications in accordance with various embodiments. Exemplarycommunications system 2200 includes a plurality of wireless terminals,e.g., mobile nodes, and a plurality of base stations. At least some ofthe plurality of base stations are both network access node and peer topeer capable such as exemplary base station 2212. Exemplarycommunications system 2220 also includes some base stations whichfunction as access nodes but do not support peer to peer communicationssuch as exemplary base station 2280 and some non-access beacon signaltransmitter nodes for supporting peer to peer communications such asexemplary non-access beacon signal transmitter node 2282.

System 2200 includes wireless terminal 1A 2202 and wireless terminal 1B2204, which both support peer to peer and cellular communications;wireless terminal 2A 2206 and wireless terminal 2B 2210, which bothsupport peer to peer communications but not cellular networkcommunications; and wireless terminal 3 2208 which supports cellularnetwork communications but not peer to peer communications.

Wireless terminal 1A 2202 includes a beacon signal processing module2216, a peer to peer communications module 2218, a cellular networkcommunications module 2230, a mode control module 2232, current modeinformation 2234 and subscriber plan identification information 2236.Beacon signal processing module 2216 processes beacon signals receivedfrom base stations and/or non-access beacon signal transmitter nodes.The beacon signals are uses for supporting cellular and peer to peercommunications, e.g., providing synchronization, identification, modeand/or priority information. Peer to peer communications module 2218performs operations supporting peer to peer communications. Cellularnetwork communications module 2230 performs operations supportingcellular communications in which the wireless terminal 1A 2202 iscommunicating via a wireless communications link with a base stationfunctioning as and access node and providing a point of networkattachment. Mode control module 2232 switches between peer to peer andcellular modes of operation, as wireless terminal 1A 2202 supports atmost one of peer to peer mode and cellular mode operation at a giventime. Current mode information 2234 indicates which of the peer to peermode and cellular mode wireless terminal 1A 2202 is currently operatingin.

Wireless terminal 1B 2204 includes a beacon signal processing module2238, a peer to peer communications module 2240, a cellular networkcommunications module 2242, a communications control module 2244, andsubscriber plan identification information 2246. Beacon signalprocessing module 2238 processes beacon signals received from basestations and/or non-access beacon signal transmitter nodes. Peer to peercommunications module 2240 performs operations supporting peer to peercommunications. Cellular network communications module 2242 performsoperations supporting cellular communications in which the wirelessterminal 1B 2204 is communicating via a wireless communications linkwith a base station functioning as an access node and providing a pointto network attachment. Communications control module 2244 switchesbetween peer to peer and cellular modes of operation, as wirelessterminal 1A 2202 controls the wireless terminal to maintain peer to peerand cellular network communications sessions at the same time.

Wireless terminal 2A 2206 includes a beacon signal processing module2248, a peer to peer communications module 2250, and subscriber planidentification information 2252. Beacon signal processing module 2248processes beacon signals received from base stations and/or non-accessbeacon signal transmitter nodes. Peer to peer communications module 2250performs operations supporting peer to peer communications. Wirelessterminal 2B 2210 includes a beacon signal processing module 2260, a peerto peer communications module 2262, and subscriber plan identificationinformation 2264. Beacon signal processing module 2260 processes beaconsignals received from base stations and/or non-access beacon signaltransmitter nodes. Peer to peer communications module 2262 performsoperations supporting peer to peer communications.

Wireless terminal 3 2208 includes a beacon signal processing module2254, a cellular network communications module 2256, and subscriber planidentification information 2258. Beacon signal processing module 2254processes beacon signals received from base stations and/or non-accessbeacon signal transmitter nodes. Cellular network communications module2256 performs operations supporting cellular network communications.

Base station 2212 includes a beacon transmission module 2213. Beaconsignal transmission module 2213 transmits beacon signals used forcommunications synchronization, identification, mode, and/or priorityinformation. In some embodiments, at least some of the beacon signalsare OFDM beacon signals including beacons signal bursts, each beaconsignal burst including at least one beacon symbol. Base station 2212 iscoupled to other network nodes, e.g., other base station, routers, AAAnodes, home agent nodes, etc, and/or the Internet via link 2214. Basestation 2280 is coupled to other network nodes and/or the Internet vianetwork link 2281. Network links 2214, 2281 are, e.g., fiber optic linksand/or wired links.

Dotted line 2268 between wireless terminal 1A 2202 and base station 2212indicates that WT 1A 2202 can operate in a cellular communication modeand have a wireless communication link with a base station. Dotted line2266 between wireless terminal 1A 2202 and WT 2A 2206 2212 indicatesthat WT 1A 2202 and WT 2A 2206 can operate in a peer to peercommunications mode and have wireless communication link with anotherwireless terminal. The lines 2266 and 2268 have been indicated as dottedlines to indicate that WT 1A 2202 switches between the two modes.

Solid line 2274 between wireless terminal 1B 2204 and base station 2212indicates that WT 1B 2204 can operate in a cellular communication modeand have a wireless communication link with a base station. Solid line2272 between wireless terminal 1B 2204 and WT 2B 2206 2210 indicatesthat WT 1B 2204 and WT 2B 2210 can operate in a peer to peercommunications mode and have a wireless communication link with anotherwireless terminal. The lines 2272 and 2274 have been indicated as solidlines to indicate that WT 1B can maintain peer to peer and cellularnetwork communications sessions at the same time.

Line 2270 between wireless terminal 3 2208 and base station 2212indicates that WT 3 2208 can operate in a cellular communication modeand have a wireless communication link with a base station.

The various wireless terminals (2202, 2204, 2206, 2208, 2210) includesubscriber plan identification information (2236, 2246, 2252, 2258,2264), respectively. In some embodiments, a set of wireless terminalscorrespond to a communications service subscriber who subscribes to afamily plan which supports multiple communications devices some of whichhave different capabilities. For example, in one embodiment, the set ofwireless terminals corresponding to the communications servicesubscriber who subscribes to a family plan includes WT 1A 2202, WT 1B2204, WT 2A 2206, and WT 3 2208.

In some embodiments, the peer to peer communications modules (2218,2240, 2250, 2262) are OFDM communications modules. In some embodimentsthe cellular network communications modules (2230, 2242, 2256) are OFDMcommunications modules. In some embodiments, the peer to peercommunications modules (2218, 2240, 2250, 2262) are OFDM communicationsmodules, and the cellular network communications modules (2230, 2242,2256) are CDMA communications modules. In some embodiments, the peer topeer communications modules (2218, 2240, 2250, 2262) are OFDMcommunications modules, and the cellular network communications modules(2230, 2242, 2256) are GSM communications modules.

FIG. 32 is a drawing 3200 illustrating exemplary beacon burst timeposition hopping in accordance with various embodiments. Horizontal axis3202 represents time while vertical axis 3204 represents frequency,e.g., OFDM tones in a frequency band, e.g., a non-infrastructurefrequency band being used for peer to peer communications. A wirelessterminal receives an external broadcast signal 3206 which the wirelessterminal uses a timing reference signal and upon which it bases itstiming structure. The external reference signal repeats as indicated bysignal 3206′. In some embodiments, the timing reference point is derivedfrom information conveyed by the received broadcast signal.

In this example, the peer to peer timing structure being used by thewireless terminal includes a sequence of slots used for beaconsignaling, each time slot is associated with a beacon signaling resource(slot 1 beacon signaling resource 3208, slot 2 beacon signaling resource3210, slot 3 beacon signaling resource 3212. The slots repeat asindicated by slot 1 beacon signaling resource 3208′. Each slot beaconsignaling resource represents a block of air link resources, e.g., OFDMtone-symbols.

The start of each beacon signaling resources slot (3208, 3210, 3212) isreferenced with respect a predetermined timing offset (T1 3214, T2 3216,T3 3218). In some embodiments, the time duration of each beaconsignaling slot is the same. In some embodiments T2−T1=T3−T2.

Within each beacon signaling slot resource (3208, 3210, 3212), thewireless terminal transmits a beacon signal burst (3220, 3222, 3224)including at least one beacon symbol (3226, 3228, 3230), the beaconsymbol being a relatively high power symbol with respect to data symbolstransmitted by the wireless terminal. In this example, the time positionof the beacon signal burst with the beacon resource slot is hopped fromone slot to the next in accordance with a hopping function used by thewireless terminal. The hopping function varies the time of the beaconsignal burst from the start of the slot as indicated by different timeoffset values (T4 3234, T5 3236, T6 3238) corresponding to (slot 1, slot2, slot 3), respectively. The hopping function determines the timeoffset as a function of a wireless terminal identifier, a useridentifier, and/or a priority level value. In some embodiments, otherinputs can be used by the hopping function, e.g., a received broadcastvalue associated with the spectrum, a received key, a value associatedwith a designated area, a value associated with a sector, etc.

In this example, the same tone is used by the wireless terminal for thebeacon symbol (3226, 3228, 3230, 3226′) of the beacon signal bursts(3220, 3220, 3224, 3220′), respectively, in slots resources (3208, 3210,3212, 3208′), respectively. Different wireless may, and sometimes do usea different tone for the beacon symbol.

FIG. 33 is a drawing 3300 illustrating exemplary beacon burst timeposition hopping and beacon symbol tone hopping in accordance withvarious embodiments. Horizontal axis 3302 represents time while verticalaxis 3304 represents frequency, e.g., OFDM tones in a frequency band,e.g., a non-infrastructure frequency band being used for peer to peercommunications. A wireless terminal receives an external broadcastsignal 3306 which the wireless terminal uses a timing reference signaland upon which it bases its timing structure. The external referencesignal repeats as indicated by signal 3306′. In some embodiments, thetiming reference point is derived from information conveyed by thereceived broadcast signal. In this example, the peer to peer timingstructure being used by the wireless terminal includes a sequence ofslots used for beacon signaling each time slot is associated with abeacon signaling resource (slot 1 beacon signaling resource 3308, slot 2beacon signaling resource 3310, slot 3 beacon signaling resource 3312).The slots repeat as indicated by slot 1 beacon signaling resource 3308′.Each slot beacon signaling resource represents a block of air linkresources, e.g., OFDM tone-symbols.

The start of each beacon signaling resources slot (3308, 3310, 3312) isreferenced with respect a predetermined timing offset (T1 3314, T2 3316,T3 3318) from the external timing reference signal 3306. In someembodiments, the time duration of each beacon signaling slot is thesame. In some embodiments T2−T1=T3−T2.

Within each beacon signaling slot resource (3308, 3310, 3312), thewireless terminal transmits a beacon signal burst (3320, 3322, 3324)including at least one beacon symbol (3326, 3328, 3330), the beaconsymbol being a relatively high power symbol with respect to data symbolstransmitted by the wireless terminal. In this example, the time positionof the beacon signal burst with the beacon resource slot is hopped fromone slot to the next in accordance with a time hopping function used bythe wireless terminal. The hopping function varies the time of thebeacon signal burst from the start of the slot as indicated by differenttime offset values (T4 3334, T5 3336, T6 3338) corresponding to (slot 1,slot 2, slot 3), respectively. The hopping function determines the timeoffset as a function of a wireless terminal identifier, a useridentifier, and/or a priority level value. In some embodiments, otherinputs can be used by the hopping function, e.g., a received broadcastvalue associated with the spectrum, a received key, a value associatedwith a designated area, a value associated with a sector, etc.

In this example, the tone of the beacon signal used by the wirelessterminal for the beacon symbol (3326, 3328, 3330) of the beacon signalbursts (3320, 3322, 3324), respectively, in slots resources (3308, 3310,3312), respectively, is also hopped from one slot to another inaccordance with a tone hopping function. Inputs to the tone hoppingfunction include one or more of a wireless terminal identifier, a useridentifier, a priority level value, a received broadcast valueassociated with the spectrum, a received key, a value associated with adesignated area, and a value associated with a sector.

In this example, the next iteration of beacon signaling resource slot 13308′ has the beacon symbol 3326′ of beacon burst 3320′ placed in thesame OFDM tone-symbol position of the resource 3308′ as the beaconsymbol 3326 of beacon burst 3320 in resource 3308. In some embodiments,two separate hopping functions are used, one for beacon burst timehopping and the other for tone hopping. In some embodiments, the beaconburst time position hopping function and the tone hopping function havethe same sequence length. In some embodiments, the beacon burst timeposition hopping functions and the tone hopping function have differentsequence lengths. For example, the two sequence lengths may be co-primewith each other. Alternatively, the ratio of one sequence length to theother sequence length may be an integer. In other embodiments, onehopping function is used for both beacon burst time hopping and tonehopping. Specifically, suppose that each beacon signaling resource slot3308, 3310, 3312 includes M symbol times and every symbol tie includes Ntones. Then, in each slot, the hopping function outputs a number, whichuniquely identifies one specific tone at one specific symbol time. Forexample, the number can be 0, 1, . . . , M*N−1, where M and N arepositive integers. In some embodiments, N is at least 100 and M is atleast 20, although in other embodiments, the values may be smaller.

FIG. 34 is a drawing 3400 illustrating exemplary coordinated timing in apeer to peer communications band in accordance with various embodiments.Drawing 3400 includes exemplary 1st and 2nd wireless terminal (3402,3404), e.g., peer mobile nodes. Upper drawing portion 3401 is used toillustrate operations of wireless terminal 1 3402, while lower drawingportion 3403 is used to illustrate operations of wireless terminal 23404. Horizontal axes 3406 represents time, while vertical axes 3408represents frequency, e.g., OFDM tones in the peer to peer frequencyband.

Both wireless terminals (3402, 3404) receive and use external broadcastsignal 3410 to obtain timing reference. Based on the timing referencesignal 3410, both wireless terminals (3402, 3404) recognize beaconsignaling resource slots 3412 and 3414. Wireless terminal 1 3402transmits a beacon signal burst 3416 including beacon symbol 3418 duringtime interval 3440, and beacon signal burst 3420 including beacon symbol3422 during time interval 3442. Wireless terminal 2 3404 is monitoringfor beacon symbols from other wireless terminals during time intervals3444, 3446, 3448, and 3450. Since time interval 3440 is with timeinterval 3446 wireless terminal 2 is able to detect the beacon symbol3418 from wireless terminal 1 3402. Since time interval 3442 is withintime interval 3450 wireless terminal 2 is able to detect the beaconsymbol 3422 from wireless terminal 1 3402.

Wireless terminal 2 3404 transmits a beacon signal burst 3424 includingbeacon symbol 3426 during time interval 3452, and beacon signal burst3428 including beacon symbol 3430 during time interval 3454. Wirelessterminal 1 3402 is monitoring for beacon symbols from other wirelessterminals during time intervals 3432, 3434, 3436, and 3438. Since timeinterval 3452 is within time interval 3432 wireless terminal 1 is ableto detect the beacon symbol 3426 from wireless terminal 2 3404. Sincetime interval 3454 is within time interval 3436 wireless terminal 1 isable to detect the beacon symbol 3430 from wireless terminal 2 3404.

In this example, both wireless terminals are able to detect beaconsignals from each other. The coordinated timing structure base on areference allows efficient operation and reduced power consumption,since modules within a wireless terminal can be powered down whentransmission and/or monitoring is not required, e.g., during silencemodes of operation.

Time hopping of the beacon burst, e.g., as a function of a wirelessterminal identifier, facilitates resolution of a problem where bothwireless terminal 1 and wireless terminal 2 should happen to transmit abeacon signal burst during one beacon signaling resource slot. In someembodiments, the beacon burst time hopping is structured so that atleast some beacon signal bursts transmitted by two peer wirelessterminals will be non-overlapping. In some embodiments, a wirelessterminal, occasionally, refrains from transmitting its beacon burstduring a beacon signaling resource and monitors for the full duration ofthe beacon signaling resource.

Additional embodiments, features and variations will now be discussed.

An infrastructure network usually includes a base station, whichprovides service to terminals in a given geographical area. In anexemplary embodiment, a base station of an infrastructure network uses afirst (infrastructure) spectrum band to provide service in ageographical area. Meanwhile, a second (non-infrastructure) spectrumband, which is different from the infrastructure spectrum band, is alsoavailable for the terminals in the area, e.g., to be used for an ad hocnetwork.

In accordance with various embodiments, in order to facilitate thetiming and/or frequency synchronization in the ad hoc network using thenon-infrastructure spectrum band, the infrastructure base stationtransmits a beacon signal.

In an exemplary embodiment, the base station transmits the beacon signalin the infrastructure spectrum band. The desired common timing and/orfrequency reference to be used in the non-infrastructure spectrum bandcan be determined from the beacon signal. In addition, the base stationmay, and sometimes does, send system information about the frequencylocation of the non-infrastructure spectrum band and the type of serviceprovided in the non-infrastructure spectrum band, e.g., TDD (timedivision duplex) or ad hoc networking. The system information is sentusing the beacon signal and/or other broadcast control signals.

A wireless terminal first tunes to the infrastructure spectrum band todetect the beacon signal and derives the timing and/or frequencyreference to be used in the non-infrastructure spectrum band. Thewireless terminal further receives the system information from thebeacon and/or other broadcast control signals, and determines thefrequency location of the non-infrastructure spectrum band, e.g.,carrier frequency. The wireless terminal tunes to the non-infrastructurespectrum band and uses the acquired timing and/or frequencysynchronization to start a communication link in the non-infrastructurespectrum band.

In another embodiment, the base station transmits the beacon signal inthe non-infrastructure spectrum band, so that if the wireless terminaldirectly tunes to the non-infrastructure spectrum band, the wirelessterminal can derive the desired common timing and/or frequency referencefrom the beacon signal. In that embodiment, the base station may, andsometimes does, additionally transmit beacon and/or other broadcastcontrol signals in the infrastructure spectrum band as well as sendsystem information about the frequency location of thenon-infrastructure spectrum band and the type of service provided in thenon-infrastructure spectrum band.

In yet another embodiment, in which the infrastructure spectrum band maynot exist, a special transmitter is set in a geographic area to transmita system beacon signal in each of the non-infrastructure spectrum bandsthat are available for use in the vicinity of the geographical area inwhich the special transmitter sits. In one embodiment, at a given time,the special transmitter transmits at most one beacon signal burst in aspectrum band. The special transmitter hops across each of the availablespectrum bands and transmits the beacon signal burst successively fromone spectrum band to another. A wireless terminal is to scan a candidatespectrum band to see whether a system beacon signal can be detected inthe candidate spectrum band. If a system beacon signal is detected, thenthe candidate spectrum band is available for use. Otherwise, thewireless terminal, in some embodiments, is not allowed to use thecandidate spectrum band, in which case the wireless terminal may have toscan another candidate spectrum band to find an available spectrum bandto use.

After the wireless terminal obtains the timing and/or frequencyreference from the beacon signal, the wireless terminal then tunes tothe non-infrastructure spectrum band. The wireless terminal, in someembodiments, starts to transmit its own user beacon signal in thenon-infrastructure spectrum band. Similar to the beacon signal sent bythe infrastructure base station, the user beacon signal also includes asequence of beacon signal bursts in a spectrum band. However, the userbeacon signal, in some embodiments, is different from the beacon signalsent by the infrastructure base station in at least one of the followingways: the periodicity of the beacon signal bursts, the tone used in abeacon signal burst, and the hopping pattern of the tones used insuccessive beacon signal bursts. The wireless terminal may, andsometimes does, further listen to the non-infrastructure spectrum bandto detect the presence of a user beacon signal sent by another wirelessterminal. In some embodiments, the wireless terminal determinetransmission and/or detection of user beacon signals as a function ofthe timing and/or frequency reference from the beacon signal sent by theinfrastructure base station. When wireless terminals derive their timingand/or frequency reference from the same source, e.g., the sameinfrastructure base station beacon signal, it is easy for them to detecteach other's presence and to establish communication links.

In accordance with a feature of some exemplary embodiments, while awireless terminal is in a peer-to-peer communication session in thenon-infrastructure spectrum band, the wireless terminal may, andsometimes does, periodically suspend the session for a short time periodand tune to the infrastructure spectrum band, e.g., to check whetherthere is a page for the terminal. The time periods in which the wirelessterminal checks pages are, in some embodiments, pre-determined, so thatboth the wireless terminal and the base station can be synchronized onwhen a page should be delivered. In some embodiments, a set of wirelessterminals in the peer-to-peer communication sessions have a common timeperiod in which each of those wireless terminals suspend the sessions inthe non-infrastructure spectrum band and check pages in theinfrastructure spectrum band. Advantageously, this synchronization helpsreduce the wastage of session time in the peer-to-peer sessions.

In accordance with various embodiments, the infrastructure base stationalso provides service in the non-infrastructure spectrum band, e.g., toprovide peer-to-peer communication service and/or to provide TDDservice. The base station in some embodiments transmits the beaconsignal in such a way that after the wireless terminal receives thebeacon signal the wireless terminal can predict the signal quality of adata session if the wireless terminal is to establish a communicationlink with the base station. In one embodiment, the transmission power ofthe beacon signal is the same for each of such base stations. In anotherembodiment, the data session, e.g., at a given coding and modulationrate, is sent at a transmission power, which is a function of thetransmission power of the beacon signal. For example, the per minimumtransmission unit transmission power of the data session is a fixed dBamount, e.g., 10 dBS or 16 dBs, below the transmission power of thebeacon symbols of the beacon signal.

While described primarily in the context of an OFDM system, the methodsand apparatus of various embodiments are applicable to a wide range ofcommunications systems including many non-OFDM, and/or many non-cellularsystems.

In various embodiments nodes described herein are implemented using oneor more modules to perform the steps corresponding to one or moremethods, for example, generating a beacon signal, transmitting a beaconsignal, receiving beacon signals, monitoring for beacon signals,recovering information from received beacon signals, determining atiming adjustment, implementing a timing adjustment, changing a mode ofoperation, initiating a communication session, etc. In some embodimentsvarious features are implemented using modules. Such modules may beimplemented using software, hardware or a combination of software andhardware. Many of the above described methods or method steps can beimplemented using machine executable instructions, such as software,included in a machine readable medium such as a memory device, e.g.,RAM, floppy disk, etc. to control a machine, e.g., general purposecomputer with or without additional hardware, to implement all orportions of the above described methods, e.g., in one or more nodes.Accordingly, among other things, various embodiments are directed to amachine-readable medium including machine executable instructions forcausing a machine, e.g., processor and associated hardware, to performone or more of the steps of the above-described method(s).

Numerous additional variations on the methods and apparatus describedabove will be apparent to those skilled in the art in view of the abovedescriptions. Such variations are to be considered within scope. Themethods and apparatus of various embodiments may be, and in variousembodiments are, used with CDMA, orthogonal frequency divisionmultiplexing (OFDM), and/or various other types of communicationstechniques which may be used to provide wireless communications linksbetween access nodes and mobile nodes. In some embodiments the accessnodes are implemented as base stations which establish communicationslinks with mobile nodes using OFDM and/or CDMA. In various embodimentsthe mobile nodes are implemented as notebook computers, personal dataassistants (PDAs), or other portable devices includingreceiver/transmitter circuits and logic and/or routines, forimplementing the methods of various embodiments.

What is claimed is:
 1. A method of operating a wireless terminal whichsupports both peer to peer communication and communication via a basestation, the method comprising: receiving a first signal from a firstcommunications band, the first signal being from a base station;determining from said first signal, link quality of a first link betweensaid base station and said wireless terminal; receiving a second signalfrom a second communications band which is different from said firstcommunications band, said second signal being from a peer wirelessterminal; determining from said second signal, link quality of a secondlink between said wireless terminal and said peer wireless terminal; andselecting between said first and second links for a communicationssession based on the determined quality of said first and second links;wherein said first signal includes a beacon signal burst transmitted bythe base station and said second signal includes a beacon signal bursttransmitted by said peer wireless terminal; and wherein said secondsignal is transmitted by said peer wireless terminal in anon-infrastructure frequency band in a time interval which is a functionof the timing of the beacon signal burst transmitted by the basestation.
 2. The method of claim 1, further comprising: predicting afirst data throughput to the base station based on said first determinedlink quality; predicting a second data throughput to the peer wirelesscommunications device base on said second determined link quality; andwherein said selecting includes selecting the one of the first andsecond links having the higher data throughput.
 3. The method of claim2, wherein predicting the first data throughput includes using maximumtransmission power information.
 4. The method of claim 3 wherein saidmaximum transmission power information includes at least one ofinformation on a government restriction on maximum transmission powerand device power output capability.
 5. The method of claim 1, whereinselecting between said first and second links for a communicationssession is also performed as a function of energy required to maintainsaid first and second links, said selecting including selecting the oneof the first and second links satisfying a link quality requirement andalso requiring the least amount of energy to maintain.
 6. The method ofclaim 1, wherein selecting between said first and second links is alsoperformed as a function of a least cost routing determination that takesinto consideration economic costs associated with using individual onesof the first and second links.
 7. The method of claim 1, furthercomprising: wherein said first and second signal each include at leastone beacon signal burst; determining the frequency hand of the secondsignal from the first signal prior to receiving said second signal. 8.The method of claim 1, further comprising: determining an interval oftime during which said wireless terminal is to monitor for said secondsignal; and monitoring during said interval to receive said secondsignal.
 9. A wireless terminal which supports both peer to peercommunication and communication via a base station, the wirelessterminal comprising: a receiver module for receiving a first signal froma first communications band, the first signal being from a base stationand for receiving a second signal from a second communications bandwhich is different from said first communications band, said secondsignal being from a peer wireless terminal; a base station link qualitydetermination module for determining from said first signal link qualityof a first link between said base station and said wireless terminal; apeer to peer link quality determination module for determining from saidsecond signal link quality of a second link between said wirelessterminal and said peer wireless terminal; and a link selection modulefor selecting between said first and second links for a communicationssession based on the determined quality of said first and second links;wherein said first signal includes a beacon signal burst transmitted bythe base station and said second signal includes a beacon signal bursttransmitted by said peer wireless terminal; and wherein said secondsignal is transmitted by said peer wireless terminal in anon-infrastructure frequency band in a time interval which is a functionof the timing of the beacon signal burst transmitted by the basestation.
 10. The wireless terminal of claim 9, further comprising: afirst data throughput determination module for predicting a first datathroughput to the base station base on said first determined linkquality; a second data throughput determination module for predicting asecond data throughput to the peer wireless communications device basedon said second determined link quality; and wherein said link selectionmodule includes a throughput based selection module for selecting theone of the first and second links having the higher data throughput. 11.The wireless terminal of claim 10, wherein said first signal includes abeacon signal burst transmitted by the base station and said secondsignal includes a beacon signal burst and wherein said second signal istransmitted by said peer wireless terminal in a non-infrastructurefrequency band in a time interval which is a function of the timing ofthe beacon signal burst transmitted by the base station; the wirelessterminal further comprising: a beacon burst processing module forrecovering link information from a beacon signal burst; and a user datarecovery module for recovering user data from non-beacon signals used tocommunicate user data as part of a communications session.
 12. Thewireless terminal of claim 11, further comprising: a data storageelement including stored maximum transmission power information; andwherein said first data throughput prediction module uses said storedmaximum transmission power information in predicting the first datathroughput.
 13. The wireless terminal of claim 12, wherein said storedmaximum transmission power information includes at least one ofinformation on a government restriction on maximum transmission powerand device power output capability.
 14. The wireless terminal of claim9, further comprising: a power requirement estimation module forestimating the amount of energy required to maintain the first andsecond links; and wherein selecting between said first and second linksfor a communications session is also performed as a function of energyrequired to maintain said first and second links, said selectingincluding selecting the one of the first and second links satisfying alink quality requirement and also requiring the least amount of energyto maintain.
 15. The wireless terminal of claim 9, further comprising: arouting cost determination module for performing a routing costdetermination that takes into consideration economic costs associatedwith using individual ones of the first and second links; and whereinselecting between said first and second links is also performed as afunction of a least cost routing determination that takes intoconsideration economic costs associated with using individual ones ofthe first and second links.
 16. The wireless terminal of claim 10,further comprising: a frequency band determination module fordetermining, prior to receiving said second signal, the frequency bandof the second signal from the first. signal.
 17. The wireless terminalof claim 10, further comprising: a monitor interval determination modulefor determining an interval of time during which said wireless terminalis to monitor for said second signal; and a peer to peer signalmonitoring module for monitoring for a signal from a peer wirelessterminal during said monitoring module for monitoring for a signal froma peer wireless terminal during said interval to receive said secondsignal.
 18. A wireless terminal which supports both peer to peercommunication and communication via a base station, the wirelessterminal comprising: receiver means for receiving a first signal from afirst communications band, the first signal being from a base stationand for receiving a second signal from a second communications bandwhich is different from said first communications band, said secondsignal being from a peer wireless terminal; base station link qualitydetermination means for determining from said first signal link qualityof a first link between said base station and said wireless terminal;peer to peer link quality determination means for determining from saidsecond signal link quality of a second link between said wirelessterminal and said peer wireless terminal; and link selection means forselecting between said first and second links for a communicationssession based on the determined quality of said first and second links;wherein said first signal includes a beacon signal burst transmitted bythe base station and said second signal includes a beacon signal bursttransmitted by said peer wireless terminal; and wherein said secondsignal is transmitted by said peer wireless terminal in anon-infrastructure frequency band in a time interval which is a functionof the timing of the beacon signal burst transmitted by the basestation.
 19. The wireless terminal of claim 18, further comprising:first data throughput determination means for predicting a first datathroughput to the base station based on said first determined linkquality; second data throughput determination means for predicting asecond data throughput to the peer wireless communications device basedon said second determined link quality; and wherein said link selectionmeans includes a throughput based selection means for selecting the oneof the first and second links having the higher data throughput.
 20. Thewireless terminal of claim 19, wherein said first signal includes abeacon signal burst transmitted by the base station and said secondsignal includes a beacon signal burst and wherein said second signal istransmitted by said peer wireless terminal in a non-infrastructurefrequency band in a time interval which is a function of the timing ofthe beacon signal burst transmitted by the base station; the wirelessterminal further comprising: beacon burst processing means forrecovering link information from a beacon signal burst; and user datarecovery means for recovering user data from non-beacon signals used tocommunicate user data as part of a communications session.
 21. Thewireless terminal of claim 18, further comprising power requirementestimation means for estimating the amount of energy required tomaintain the first and second links; and wherein selecting between saidfirst and second links for a communications session is also performed asa function of energy required to maintain said first and second links,said selecting including selecting the one of the first and second linkssatisfying a link quality requirement and also requiring the leastamount of energy to maintain.
 22. The wireless terminal of claim 18,further comprising routing cost determination means for performing arouting cost determination that takes into consideration economic costsassociated with using individual ones of the first and second links; andwherein selecting between said first and second links is also performedas a function of a least cost routing determination that takes intoconsideration economic costs associated with using individual ones ofthe first and second links.
 23. The wireless terminal of claim 19,further comprising: frequency band determination means for determining,prior to receiving said second signal, the frequency band of the secondsignal from the first signal.
 24. The wireless terminal of claim 19,further comprising: monitor interval determination means for determiningan interval of time during which said wireless terminal is to monitorfor said second signal; and peer to peer signal monitor means formonitoring for a signal from a peer wireless terminal during saidinterval to receive said second signal.
 25. A non-transitory computerreadable medium embodying machine executable instructions forcontrolling a wireless terminal which supports both peer to peercommunication and communication via a base station, the machineexecutable instructions comprising: instructions for receiving a firstsignal from a first communications band, the first signal being from abase station; instructions for determining from said first signal linkquality of a first link between said base station and said wirelessterminal; instructions for receiving a first signal from a firstcommunications band, the first signal being from a base station and forreceiving a second signal from a second communications band which isdifferent from said first communications band, said second signal beingfrom a peer wireless terminal; instructions for determining from saidfirst signal link quality of a first link between said base station andthe apparatus; determine from said second signal link quality of asecond link between said Apparatus and said peer wireless terminal; andinstructions for selecting between said first and second links for acommunications session based on the determined quality of said first andsecond links; wherein said first signal includes a beacon signal bursttransmitted by the base station and said second signal includes a beaconsignal burst transmitted by said peer wireless terminal; and whereinsaid second signal is transmitted by said peer wireless terminal in anon-infrastructure frequency band in a time interval which is a functionof the timing of the beacon signal burst transmitted by the basestation.